HomeMy WebLinkAboutDune Palms Noise Study Report Combined to Caltrans 9-30-16DUNE PALMS ROAD LOW WATER CROSSING
REPLACEMENT PROJECT
Noise Study Report
DUNE PALMS ROAD LOW WATER CROSSING REPLACEMENT PROJECT
City of La Quinta, Riverside County
08-Riv-Local Assistance
Federal Project Number BLRKS-5433(014)
September 2016
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Dune Palms Road Low Water Crossing Replacement Noise Study Report iii
Noise Study Report
Dune Palms Road Low Water Crossing Replacement
In the
City of La Quinta, Riverside County
08-Riv-Local Assistance
Federal Project Number BLRKS-5433(014)
September 2016
Prepared By:Date: 9/20/16
Michael Lieu, Lead Environmental Planner
Phone Number 714-973-4880 x771
Office Name WSP|Parsons Brinckerhoff
QA/QC By:Date: 9/20/16
Kevin Keller, Acoustic/Noise Specialist
Phone Number 714-973-4880 x775
Office Name WSP|Parsons Brinckerhoff
District/Region Orange, CA
Approved By:
Date:9/28/2016
Lorraine Ahlquist, Environmental Manager-Transportation
Phone Number 619-321-4185
Office Name WSP|Parsons Brinckerhoff
District/Region San Diego, CA
Concurred By:
Date:
Olufemi A. Odufalu, Office Chief
Environmental Engineering Oversight
Caltrans District 8
Summary
Summary
Dune Palms Road is a secondary arterial in the City of La Quinta that provides a
north/south link between residential developments to the north and commercial activity to
the south near the Highway 111 corridor. It is an important connection to schools and
emergency services access to the community. Currently the elevation of the existing
Dune Palms Road low-water crossing causes it to flood during minor rain events making
it impassable. Therefore the City of La Quinta has decided to construct a new bridge to
ensure that all-weather access is maintained.
The new bridge and roadway will be 86 feet wide and a cross section that includes a six-
foot sidewalk on both sides of the bridge, two eight-foot outside shoulders also serving as
bike/golf cart lanes, a 10’ raised median, two eleven-foot travel lanes, and two twelve-
foot travel lanes.
The main purpose of the project is to provide safe access across the Coachella Valley
Storm Water Channel (CVSC) during all-weather events; provide a reliable route for
emergency vehicles, motorists, pedestrians, and bicyclists; and the improved roadway
will achieve the City’s General Plan goals for the corridor.
Land uses within the study area include commercial, residential, church and school. The
area is generally flat with the exception of the existing roadway being within the river
bed. The study area was broken down into two areas.
x Area A:Located on the northeast side of Dune Palms Road between CVSC and
Westward Ho Drive. A mobile home park (Activity Category B) and a church
(Activity Category C-D) are located in this area. This area is generally flat.
Backyards face the street. A four to five foot tall wooden fence shields the
residences in this area. (Refer to Figure 5-1.)
x Area B:Located on the northwest side of Dune Palms Road between CVSC and
Westward Ho Drive. La Quinta High School (Activity Category C-D) is located in
this area. This area is generally flat. No sound barrier or topographical shielding
occurs between the roadway and the high school area. (Refer to Figure 5-1.)
Summary
x Area C - South of Coachella Valley Storm Water Channel (CVSC):No sensitive
receivers were found in this area. This area consist of commercial building and a
commercial zoned vacant lot.
The existing traffic noise in Area A is predicted to be between 53 and 65 dBA Leq(h). The
traffic noise modeling results indicate that traffic noise levels at the church and
residences in Area A are predicted to be in the range of 60 to 64 dBA Leq(h) in the
design-year with Project. The results also indicate that the increase in noise between
existing conditions and the design-year with Project is predicted to be 1 to 8 dB. Because
the noise levels in the design-year are not predicted to approach or exceed the noise
abatement criterion (67 dBA L eq[h]) or result in a substantial increase in noise, no traffic
noise impacts are predicted in Area A.
The church has an interior noise abatement criterion in addition to the exterior criterion,
interior noise must be considered at the church as well. From Table 6 in the FHWA
Highway Traffic Noise Analysis and Abatement Guidance document, the building noise
reduction factor for standard construction with ordinary windows closed is 20 dB. The
interior noise level in the church in the design-year is therefore predicted to be 44 dBA
Leq(h). Because this predicted design-year noise level does not exceed the interior NAC
of 52 dBA Leq(h), no interior traffic noise impacts are predicted at the church.
The existing traffic noise in Area B is predicted to be 55 dBA Leq(h). Levels at the school
in Area B are predicted to be 60 to 61 dBA Leq(h) in the design-year with Project. The
results also indicate that the increase in noise between existing conditions and the design-
year with Project is predicted to be 5 to 6 dB. Because the noise levels in the design-year
with Project are not predicted to approach or exceed the noise abatement criterion (67
dBA Leq[h]) or result in a substantial increase in noise, no traffic noise impacts are
predicted in Area B.
The existing traffic noise in Area C is predicted to be 63 dBA Leq(h). The level at the
vacant lot in Area C is predicted to be 69 dBA Leq(h) in the design-year with Project.
The results also indicate that the increase in noise between existing conditions and the
design-year with Project is predicted to be 6 dB. Because the noise levels in the design-
year with Project are not predicted to approach or exceed the noise abatement criterion
(72 dBA Leq[h]) or result in a substantial increase in noise, no traffic noise impacts are
predicted in Area C.
Summary
During construction of the project, noise from construction activities may intermittently
dominate the noise environment in the immediate area of construction. To minimize the
construction generated noise impact the standard specification 14-8.02 and SSP 14-8.02
or by La Quinta’s Municipal Code, Section 6.08.050 will be followed. No adverse noise
impacts from construction are anticipated because construction would be conducted in
accordance with the City’s Municipal Code. Construction noise would be short-term,
intermittent, and overshadowed by local traffic noise.
Dune Palms Road Low Water Crossing Replacement Noise Study Report vii
Table of Contents
Chapter 1.Introduction ...................................................................................................... 1
1.1.Project Purpose and Need .................................................................................... 1
Chapter 2.Project Description ........................................................................................... 4
2.1.No-Build ............................................................................................................. 4
2.2.Build Alternative ................................................................................................. 4
Chapter 3.Fundamentals of Traffic Noise.......................................................................... 8
3.1.Sound, Noise, and Acoustics ................................................................................ 8
3.1.Frequency ............................................................................................................ 8
3.2.Sound Pressure Levels and Decibels .................................................................... 8
3.3.Addition of Decibels ............................................................................................ 9
3.4.A-Weighted Decibels ........................................................................................... 9
3.5.Human Response to Changes in Noise Levels .................................................... 10
3.6.Noise Descriptors .............................................................................................. 10
3.7.Sound Propagation ............................................................................................. 11
3.7.1.Geometric Spreading .......................................................................................... 11
3.7.2.Ground Absorption............................................................................................. 12
3.7.3.Atmospheric Effects ........................................................................................... 12
3.7.4.Shielding by Natural or Human-Made Features .................................................. 12
Chapter 4.Federal Regulations and State Policies ............................................................ 14
4.1.Federal Regulations ........................................................................................... 14
4.1.1.23 CFR 772 ........................................................................................................ 14
4.1.2.Traffic Noise Analysis Protocol for New Highway Construction and
Reconstruction Projects ..................................................................................... 15
4.2.State Regulations and Policies............................................................................ 16
4.2.1.California Environmental Quality Act (CEQA) .................................................. 16
4.2.2.Section 216 of the California Streets and Highways Code ................................... 17
Chapter 5.Study Methods and Procedures ....................................................................... 18
5.1.Methods for Identifying Land Uses and Selecting Noise Measurement and
Modeling Receiver Locations ................................................................................................ 18
5.2.Field Measurement Procedures .......................................................................... 18
5.2.1.Short-Term Measurements ................................................................................. 18
5.2.2.Long -Term Measurements ................................................................................. 20
5.3.Traffic Noise Levels Prediction Methods ........................................................... 20
5.4.Methods for Identifying Traffic Noise Impacts and Consideration of Abatement 21
Chapter 6.Existing Noise Environment ........................................................................... 23
6.1.Existing Land Uses ............................................................................................ 23
6.2.Noise Measurement Results ............................................................................... 24
6.2.1.Short-Term Monitoring ...................................................................................... 24
6.2.2.Long-Term Monitoring ...................................................................................... 24
Chapter 7.Future Noise Environment, Impacts, and Considered Abatement .................... 27
7.1.Future Noise Environment and Impacts .............................................................. 27
7.2.Preliminary Noise Abatement Analysis .............................................................. 28
7.2.1.Area A ............................................................................................................... 29
7.2.2.Area B ............................................................................................................... 29
7.2.3.Area C ............................................................................................................... 29
Chapter 8.Construction Noise ......................................................................................... 30
Appendix A Traffic Data ................................................................................................ 33
Dune Palms Road Low Water Crossing Replacement Noise Study Report viii
Appendix B Predicted Future Noise Levels and Noise Barrier Analysis .......................... 37
Appendix C Supplemental Data...................................................................................... 39
List of Figures
Figure 1-1. Project Vicinity Map ...................................................................................... 2
Figure 1-2. Project Location Map.................................................................................... 3
Figure 2-1. Noise Study Area ......................................................................................... 7
Figure 5-1. Analysis Areas, Noise Monitoring Positions, and Location of Evaluated
Noise Barrier .......................................................................................................... 19
Figure 6-1. Long-Term Measurement at Location LT-1, July 18-19, 2016 .................... 26
List of Tables
Page
Table 3-1. Typical A-Weighted Noise Levels .................................................................. 9
Table 6-1. Summary of Short-Term Measurements ...................................................... 24
Table 6-2. Summary of Long-Term Measurements ...................................................... 24
Table 6-3. Comparison of Measured to Predicted Sound Levels in the TNM Model ..... 26
Table 8-1. Construction Equipment Noise .................................................................... 30
Table A-1. Traffic Data for Existing Conditions ............................................................. 34
Table A-2. Traffic Data for Design Year No-Project Conditions..................................... 35
Table A-3. Traffic Data for Design Year with Project Conditions ................................... 36
Table A-4. Traffic Data for Validation ………………………………………………………..36
Table B-1. Predicted Future Noise and Barrier Analysis ................................................ 38
Dune Palms Road Low Water Crossing Replacement Noise Study Report ix
List of Abbreviated Terms
CEQA California Environmental Quality Act
CFR Code of Federal Regulations
CNEL
CVSC
Community Noise Equivalent Level
Coachella Valley Storm Water Channel
dB Decibels
FHWA Federal Highway Administration
Hz Hertz
kHz Kilohertz
Ldn Day-Night Level
Leq Equivalent Sound Level
Leq(h)Equivalent Sound Level over one hour
Lmax Maximum Sound Level
LOS Level of Service
Lxx Percentile-Exceeded Sound Level
mPa micro-Pascals
mph miles per hour
NAC noise abatement criteria
NADR Noise Abatement Decision Report
NEPA National Environmental Policy Act
NSR Noise Study Report
Protocol Caltrans Traffic Noise Analysis Protocol for New Highway Construction,
Reconstruction, and Retrofit Barrier Projects
SPL sound pressure level
TeNS Caltrans’Technical Noise Supplement
TNM 2.5 FHWA Traffic Noise Model Version 2.5
Dune Palms Road Low Water Crossing Replacement Noise Study Report 1
Chapter 1. Introduction
The purpose of this NSR is to evaluate noise impacts and abatement under the
requirements of Title 23, Part 772 of the Code of Federal Regulations (23 CFR 772)
“Procedures for Abatement of Highway Traffic Noise.” 23 CFR 772 provides procedures
for preparing operational and construction noise studies and evaluating noise abatement
considered for federal and Federal-aid highway projects. According to 23 CFR 772.3, all
highway projects that are developed in conformance with this regulation are deemed to
be in conformance with Federal Highway Administration (FHWA) noise standards.
Compliance with 23 CFR 772 provides compliance with the noise impact assessment
requirements of the National Environmental Policy Act (NEPA).
The Caltrans Traffic Noise Analysis Protocol for New Highway Construction,
Reconstruction, and Retrofit Barrier Projects (Protocol) (Caltrans 2011) provides Caltrans
policy for implementing 23 CFR 772 in California. The Protocol outlines the
requirements for preparing noise study reports (NSR). Noise impacts associated with this
project under the California Environmental Quality Act (CEQA) are evaluated separately
in the project’s environmental document.
1.1. Project Purpose and Need
The purpose of the project is to replace the existing low-water crossing spanning the
Coachella Valley Storm Water Channel (CVSC) at Dune Palms Road with an all-weather
access. The proposed improvements will accomplish the following in the project area:
x Provide safe access across the CVSC (Whitewater River) during all-weather
events
x Provide reliable route for emergency vehicles, motorists, pedestrians, and
bicyclists
x Achieve the City’s General Plan goals for the corridor
Dune Palms Road serves a vital access for emergency services within the project area, as
well as for La Quinta High, John Glen Middle and Amelia Earhart Elementary Schools. It
also provides connectivity of the city residential development north of the Channel with
the Highway 111 commercial corridor located south of the CVSC (Figure 1-1 and
Figure 1-2).
Chapter 1 Introduction
Dune Palms Road Low Water Crossing Replacement Noise Study Report 2
Figure 1-1. Project Vicinity Map
Chapter 1 Introduction
Dune Palms Road Low Water Crossing Replacement Noise Study Report 3
Figure 1-2. Project Location Map
The CVSC conveys storm water runoff from the surrounding mountains as well as
developed areas within the Coachella Valley. The elevation of the existing Dune
Palms Road low-water crossing causes it to flood during minor rain events (2-year
frequency) and results in full street closure and detour of both vehicle and pedestrian
traffic. In the interest of public health and safety, and in response to community
concerns regarding frequent closures of the low-water crossing, the City of La Quinta
has determined that replacement of the low-water crossing with a new bridge is
needed to ensure that all-weather access is maintained. The Dune Palms Road low-
water crossing is the last remaining low-water crossing of the CVSC within the City.
Dune Palms Road Low Water Crossing Replacement Noise Study Report 4
Chapter 2. Project Description
The project proposes to remove the existing low-water crossing of Dune Palms Road at
the CVSC in the City of La Quinta, Riverside County. The crossing will be replaced with
a 480 feet long and 86 feet wide four-span bridge. The bridge typical section consists of
six-foot sidewalk on both sides of the bridge, two (2) eight-foot outside shoulders also
serving as bike/golf cart lanes, a 10 foot wide raised median, two (2) eleven-foot travel
lanes, and two (2) twelve-foot travel lanes.
2.1. No-Build
Under the No-Build Alternative, no changes would be made to Dune Palms Road in the
project area. The existing roadway crosses the CVSC at the channel grade. The roadway
width is 68 feet at the crossing, and consists of one northbound and two southbound
through lanes, eight foot wide walkway area along the western edge, and an eight foot
shoulder along the eastern edge of the road; and no median. The existing roadway
approach south of the crossing consists of one northbound and two southbound through
lanes. The northern roadway approach consists of one through lane in each direction. The
transition from one to two lanes in the southbound direction occurs at the midpoint of the
channel crossing. Dune Palms Road approximately one-quarter mile north of the channel
low-water crossing and just south of the project limits is a four lane roadway with a
median. The roadway section just north of the crossing will be widened as part of an
approved City project (City Project Number 2009-04 per the City’s current CIP). The
City widening project was originally with a Mitigated Negative Declaration under CEQA
in April 2010.
2.2. Build Alternative
The project proposes to remove the existing low-water crossing of Dune Palms Road at
the CVSC in the City of La Quinta, Riverside County. The crossing will be replaced with
a 480 feet long and 86 feet wide four-span bridge. The bridge typical section consists of
six-foot sidewalk on both sides of the bridge, two (2) eight-foot outside shoulders also
serving as bike/golf cart lanes, a 10 foot raised median, two (2) eleven-foot travel lanes,
and two (2) twelve-foot travel lanes.
The proposed configuration will be consistent with the existing four lane roadway section
to the south, and the City’s current improvement project to the north (City Project
Chapter 2 Project Description
Dune Palms Road Low Water Crossing Replacement Noise Study Report 5
Number 2009-04), which will widen Dune Palms Road from two to four lanes with a
median and left turn lanes.
The proposed improvements will include reconstruction of the north and south bridge
approaches to accommodate the significant raised profile of the roadway. In order to
match the roadway section on the south side of the bridge, the project’s construction
limits will be extended to just north of Highway 111. On the north side of the bridge, the
project construction limits will be extended to include a vacant lot immediately north of
the project limits. The vacant lot is owned by the City and will be offered by the City in
the bidding documents to be used for storage and construction staging by the contractor
for the construction of this project.
As a part of the bridge construction, concrete slope protection will be installed along the
north side of the channel. Additionally, minor removal and replacement of slope
protection will be required on the south side of channel west of the proposed bridge and
extension of slope protection approximately 300 feet downstream of the proposed bridge.
The slope protection is needed for scour countermeasures. As a result of the proposed
cast-in-place drilled shaft bridge construction, scour protection within the bottom of the
channel should not be required.
The project will also include the following additional improvements:
• Railing Architectural treatment. The bridge design will incorporate railing
architectural treatment as required by the City’s standard design.
• Integration of a regional Bike/Pedestrian/NEV corridor (CV Link). The
Coachella Valley Association of Governments (CVAG) and the communities
within the Coachella Valley are working together on the implementation of a
regional Bike/Pedestrian/NEV corridor (CV Link) along Whitewater River
and Coachella Valley Storm Water Channel. The project design will be
consistent with these plans by allowing for the integration of a trail under
crossing within the southern slope protection, which also includes a trail
connector to the pedestrian and bike facilities proposed along Dune Palms
Road in the project area.
• Utility Relocation. The project will also require utility relocations for
overhead electrical distribution lines (Imperial Irrigation District facility),
adjustment to both water valve can and lids and the manhole covers, minor
Chapter 2 Project Description
Dune Palms Road Low Water Crossing Replacement Noise Study Report 6
12” ductile iron pipe water main relocations at each bridge abutment, and
relocation of both a 12” and 18” sewer line at the northern bridge abutment.
Right-of-Way Requirements
The project will require right-of-way acquisition on the northeast and southeast corners of
the proposed bridge. The existing development at the northeast corner of the proposed
bridge consists of a Mobile Home Park with one single family home. Some of the mobile
homes adjacent to the Dune Palms Road are encroaching within the street right of way.
The project may require the acquisition of the single-family residence and relocation of
two mobile homes residents. The project will be designed to avoid and minimize
relocation impacts of the mobile homes. At the southeast corner of the crossing, the
existing parcel is currently an undeveloped commercial parcel. Acquisition for the
vacant parcel will consist of a strip acquisition parallel with Dune Palms Road.
Temporary Construction Bypass
The existing roadway will be modified to construct a temporary bypass road. The
temporary bypass will allow for staged construction of the bridge, and maintaining
vehicle and pedestrian access at all times. Temporary and short term access impact may
occur during construction, and will require coordination with property owners, the public,
and other stakeholders.
Noise Study Area
The study area for this project includes the segment of Dune Palms Road between
Highway 111 and Westward Ho Drive/Blackhawk Way. The study also includes the two
signalized intersections on either side of this segment of Dune Palms Road that is being
reconstructed. The study intersections and segment are shown in Figure 2-1 and listed
below.
Chapter 2 Project Description
Dune Palms Road Low Water Crossing Replacement Noise Study Report 7
Figure 2-1 Noise Study Area
1.Dune Palms Road and Westward Ho Drive/Blackhawk Way
2.Dune Palms Road and Highway 111
This report presents the analysis of the following three study scenarios:
x Existing Conditions – operation of the intersections and roadway segment with
existing traffic volumes
x Future 2040 No-Build Conditions – operation of the intersections and roadway
segment with future traffic volumes and existing roadway geometrics (i.e. number
of lanes)
x Future 2040 Build Conditions – operation of the intersection and roadway
segment with future traffic volumes and proposed roadway reconstructions
geometrics
Dune Palms Road Low Water Crossing Replacement Noise Study Report 8
Chapter 3. Fundamentals of Traffic Noise
The following is a brief discussion of fundamental traffic noise concepts. For a detailed
discussion, please refer to Caltrans’ Technical Noise Supplement (TeNS) (Caltrans
2013), a technical supplement to the Protocol that is available on Caltrans Web site
(http://www.dot.ca.gov/hq/env/noise/pub/TeNS_Sept_2013B.pdf).
3.1. Sound, Noise, and Acoustics
Sound can be described as the mechanical energy of a vibrating object transmitted by
pressure waves through a liquid or gaseous medium (e.g., air) to a hearing organ, such as
a human ear. Noise is defined as loud, unexpected, or annoying sound.
In the science of acoustics, the fundamental model consists of a sound (or noise) source, a
receptor, and the propagation path between the two. The loudness of the noise source
and obstructions or atmospheric factors affecting the propagation path to the receptor
determine the sound level and characteristics of the noise perceived by the receptor. The
field of acoustics deals primarily with the propagation and control of sound.
3.1. Frequency
Continuous sound can be described by frequency (pitch) and amplitude (loudness). A
low-frequency sound is perceived as low in pitch. Frequency is expressed in terms of
cycles per second, or Hertz (Hz) (e.g., a frequency of 250 cycles per second is referred to
as 250 Hz). High frequencies are sometimes more conveniently expressed in kilohertz
(kHz), or thousands of Hertz. The audible frequency range for humans is generally
between 20 Hz and 20,000 Hz.
3.2. Sound Pressure Levels and Decibels
The amplitude of pressure waves generated by a sound source determines the loudness of
that source. Sound pressure amplitude is measured in micro-Pascals (mPa). One mPa is
approximately one hundred billionth (0.00000000001) of normal atmospheric pressure.
Sound pressure amplitudes for different kinds of noise environments can range from less
than 100 to 100,000,000 mPa. Because of this huge range of values, sound is rarely
expressed in terms of mPa. Instead, a logarithmic scale is used to describe sound
pressure level (SPL) in terms of decibels (dB). The threshold of hearing for young
people is about 0 dB, which corresponds to 20 mPa.
Chapter 3 Fundamentals of Traffic Noise
Dune Palms Road Low Water Crossing Replacement Noise Study Report 9
3.3. Addition of Decibels
Because decibels are logarithmic units, SPL cannot be added or subtracted through
ordinary arithmetic. Under the decibel scale, a doubling of sound energy corresponds to
a 3-dB increase. In other words, when two identical sources are each producing sound of
the same loudness, the resulting sound level at a given distance would be 3 dB higher
than one source under the same conditions. For example, if one automobile produces an
SPL of 70 dB when it passes an observer, two cars passing simultaneously would not
produce 140 dB—rather, they would combine to produce 73 dB. Under the decibel scale,
three sources of equal loudness together produce a sound level 5 dB louder than one
source.
3.4. A-Weighted Decibels
The decibel scale alone does not adequately characterize how humans perceive noise.
The dominant frequencies of a sound have a substantial effect on the human response to
that sound. Although the intensity (energy per unit area) of the sound is a purely physical
quantity, the loudness or human response is determined by the characteristics of the
human ear.
Human hearing is limited in the range of audible frequencies as well as in the way it
perceives the SPL in that range. In general, people are most sensitive to the frequency
range of 1,000–8,000 Hz, and perceive sounds within that range better than sounds of the
same amplitude in higher or lower frequencies. To approximate the response of the
human ear, sound levels of individual frequency bands are weighted, depending on the
human sensitivity to those frequencies. Then, an “A-weighted” sound level (expressed in
units of dBA) can be computed based on this information.
The A-weighting network approximates the frequency response of the average young ear
when listening to most ordinary sounds. When people make judgments of the relative
loudness or annoyance of a sound, their judgments correlate well with the A-scale sound
levels of those sounds. Other weighting networks have been devised to address high
noise levels or other special problems (e.g., B-, C-, and D-scales), but these scales are
rarely used in conjunction with highway-traffic noise. Noise levels for traffic noise
reports are typically reported in terms of A-weighted decibels or dBA. Table 3-1
describes typical A-weighted noise levels for various noise sources.
Table 3-1. Typical A-Weighted Noise Levels
Common Outdoor Activities Noise Level Common Indoor Activities
Chapter 3 Fundamentals of Traffic Noise
Dune Palms Road Low Water Crossing Replacement Noise Study Report 10
(dBA)
—110 —Rock band
Jet fly-over at 1000 feet
—100 —
Gas lawn mower at 3 feet
—90 —
Diesel truck at 50 feet at 50 mph Food blender at 3 feet
—80 —Garbage disposal at 3 feet
Noisy urban area, daytime
Gas lawn mower, 100 feet —70 —Vacuum cleaner at 10 feet
Commercial area Normal speech at 3 feet
Heavy traffic at 300 feet —60 —
Large business office
Quiet urban daytime —50 —Dishwasher next room
Quiet urban nighttime —40 —Theater, large conference room (background)
Quiet suburban nighttime
—30 —Library
Quiet rural nighttime Bedroom at night, concert hall (background)
—20 —
Broadcast/recording studio
—10 —
Lowest threshold of human hearing —0 —Lowest threshold of human hearing
Source:Caltrans 2013.
3.5. Human Response to Changes in Noise Levels
As discussed above, doubling sound energy results in a 3-dB increase in sound.
However, given a sound level change measured with precise instrumentation, the
subjective human perception of a doubling of loudness will usually be different than what
is measured.
Under controlled conditions in an acoustical laboratory, the trained, healthy human ear is
able to discern 1-dB changes in sound levels, when exposed to steady, single-frequency
(“pure-tone”) signals in the midfrequency (1,000 Hz–8,000 Hz) range. In typical noisy
environments, changes in noise of 1 to 2 dB are generally not perceptible. However, it is
widely accepted that people are able to begin to detect sound level increases of 3 dB in
typical noisy environments. Further, a 5-dB increase is generally perceived as a
distinctly noticeable increase, and a 10-dB increase is generally perceived as a doubling
of loudness. Therefore, a doubling of sound energy (e.g., doubling the volume of traffic
on a highway) that would result in a 3-dB increase in sound, would generally be
perceived as barely detectable.
3.6. Noise Descriptors
Noise in our daily environment fluctuates over time. Some fluctuations are minor, but
some are substantial. Some noise levels occur in regular patterns, but others are random.
Chapter 3 Fundamentals of Traffic Noise
Dune Palms Road Low Water Crossing Replacement Noise Study Report 11
Some noise levels fluctuate rapidly, but others slowly. Some noise levels vary widely,
but others are relatively constant. Various noise descriptors have been developed to
describe time-varying noise levels. The following are the noise descriptors most
commonly used in traffic noise analysis.
x Equivalent Sound Level (Leq): Leq represents an average of the sound energy
occurring over a specified period. In effect, Leq is the steady-state sound level
containing the same acoustical energy as the time-varying sound that actually occurs
during the same period. The 1-hour A-weighted equivalent sound level (Leq[h]) is
the energy average of A-weighted sound levels occurring during a one-hour period,
and is the basis for noise abatement criteria (NAC) used by Caltrans and FHWA.
x Percentile-Exceeded Sound Level (Lxx): Lxx represents the sound level exceeded
for a given percentage of a specified period (e.g., L10 is the sound level exceeded
10% of the time, and L90 is the sound level exceeded 90% of the time).
x Maximum Sound Level (Lmax): Lmax is the highest instantaneous sound level
measured during a specified period.
x Day-Night Level (Ldn): Ldn is the energy average of A-weighted sound levels
occurring over a 24-hour period, with a 10-dB penalty applied to A-weighted sound
levels occurring during nighttime hours between 10 p.m. and 7 a.m.
x Community Noise Equivalent Level (CNEL): Similar to Ldn, CNEL is the energy
average of the A-weighted sound levels occurring over a 24-hour period, with a 10-
dB penalty applied to A-weighted sound levels occurring during the nighttime hours
between 10 p.m. and 7 a.m., and a 5-dB penalty applied to the A-weighted sound
levels occurring during evening hours between 7 p.m. and 10 p.m.
3.7. Sound Propagation
When sound propagates over a distance, it changes in level and frequency content. The
manner in which noise reduces with distance depends on the following factors.
3.7.1. Geometric Spreading
Sound from a localized source (i.e., a point source) propagates uniformly outward in a
spherical pattern. The sound level attenuates (or decreases) at a rate of 6 decibels for
each doubling of distance from a point source. Highways consist of several localized
noise sources on a defined path, and hence can be treated as a line source, which
approximates the effect of several point sources. Noise from a line source propagates
Chapter 3 Fundamentals of Traffic Noise
Dune Palms Road Low Water Crossing Replacement Noise Study Report 12
outward in a cylindrical pattern, often referred to as cylindrical spreading. Sound levels
attenuate at a rate of 3 decibels for each doubling of distance from a line source.
3.7.2. Ground Absorption
The propagation path of noise from a highway to a receptor is usually very close to the
ground. Noise attenuation from ground absorption and reflective-wave canceling adds to
the attenuation associated with geometric spreading. Traditionally, the excess attenuation
has also been expressed in terms of attenuation per doubling of distance. This
approximation is usually sufficiently accurate for distances of less than 200 feet. For
acoustically hard sites (i.e., sites with a reflective surface between the source and the
receptor, such as a parking lot or body of water,), no excess ground attenuation is
assumed. For acoustically absorptive or soft sites (i.e., those sites with an absorptive
ground surface between the source and the receptor, such as soft dirt, grass, or scattered
bushes and trees), an excess ground-attenuation value of 1.5 decibels per doubling of
distance is normally assumed. When added to the cylindrical spreading, the excess
ground attenuation results in an overall drop-off rate of 4.5 decibels per doubling of
distance.
3.7.3. Atmospheric Effects
Receptors located downwind from a source can be exposed to increased noise levels
relative to calm conditions, whereas locations upwind can have lowered noise levels.
Sound levels can be increased at large distances (e.g., more than 500 feet) from the
highway due to atmospheric temperature inversion (i.e., increasing temperature with
elevation). Other factors such as air temperature, humidity, and turbulence can also have
significant effects.
3.7.4. Shielding by Natural or Human-Made Features
A large object or barrier in the path between a noise source and a receptor can
substantially attenuate noise levels at the receptor. The amount of attenuation provided
by shielding depends on the size of the object and the frequency content of the noise
source. Natural terrain features (e.g., hills and dense woods) and human-made features
(e.g., buildings and walls) can substantially reduce noise levels. Walls are often
constructed between a source and a receptor specifically to reduce noise. A barrier that
breaks the line of sight between a source and a receptor will typically result in at least 5
dB of noise reduction. Taller barriers provide increased noise reduction. Vegetation
between the highway and receptor is rarely effective in reducing noise because it does not
create a solid barrier.
Dune Palms Road Low Water Crossing Replacement Noise Study Report 14
Chapter 4. Federal Regulations and State
Policies
This report focuses on the requirements of 23 CFR 772, as discussed below.
4.1. Federal Regulations
4.1.1. 23 CFR 772
23 CFR 772 provides procedures for preparing operational and construction noise studies
and evaluating noise abatement considered for federal and Federal-aid highway projects.
Under 23 CFR 772.7, projects are categorized as Type I, Type II, or Type III projects.
x FHWA defines a Type I project as a proposed federal or federal-aid highway
project for the construction of a highway on a new location or the physical
alteration of an existing highway which significantly changes either the horizontal
or vertical alignment of the highway. The following projects are also considered
to be Type I projects:
x The addition of a through-traffic lane(s). This includes the addition of a through-
traffic lane that functions as a high-occupancy vehicle (HOV) lane, high-
occupancy toll (HOT) lane, bus lane, or truck climbing lane,
x The addition of an auxiliary lane, except for when the auxiliary lane is a turn lane,
x The addition or relocation of interchange lanes or ramps added to a quadrant to
complete an existing partial interchange,
x Restriping existing pavement for the purpose of adding a through traffic lane or
an auxiliary lane,
x The addition of a new or substantial alteration of a weigh station, rest stop, ride-
share lot, or toll plaza.
If a project is determined to be a Type I project under this definition, the entire project
area as defined in the environmental document is a Type I project.
A Type II project is a noise barrier retrofit project that involves no changes to highway
capacity or alignment. A Type III project is a project that does not meet the
Chapter 4 Federal Regulations and State Policies
Dune Palms Road Low Water Crossing Replacement Noise Study Report 15
classifications of a Type I or Type II project. Type III projects do not require a noise
analysis.
Under 23 CFR 772.11, noise abatement must be considered for Type I projects if the
project is predicted to result in a traffic noise impact. In such cases, 23 CFR 772 requires
that the project sponsor “consider” noise abatement before adoption of the final NEPA
document. This process involves identification of noise abatement measures that are
reasonable, feasible, and likely to be incorporated into the project, and of noise impacts
for which no apparent solution is available.
Traffic noise impacts, as defined in 23 CFR 772.5, occur when the predicted noise level
in the design-year approaches or exceeds the NAC specified in 23 CFR 772, or a
predicted noise level substantially exceeds the existing noise level (a “substantial” noise
increase). 23 CFR 772 does not specifically define the terms “substantial increase” or
“approach”; these criteria are defined in the Protocol, as described below.
Table 4-1 summarizes NAC corresponding to various land use activity categories.
Activity categories and related traffic noise impacts are determined based on the actual or
permitted land use in a given area.
4.1.2. Traffic Noise Analysis Protocol for New Highway Construction and
Reconstruction Projects
The Protocol specifies the policies, procedures, and practices to be used by agencies that
sponsor new construction or reconstruction of federal or Federal-aid highway projects.
The Protocol defines a noise increase as substantial when the predicted noise levels with
project implementation exceed existing noise levels by 12 dBA or more. The Protocol
also states that a sound level is considered to approach an NAC level when the sound
level is within 1 dB of the NAC identified in 23 CFR 772 (e.g., 66 dBA is considered to
approach the NAC of 67 dBA, but 65 dBA is not).
The Technical Noise Supplement to the Protocol provides detailed technical guidance for
the evaluation of highway traffic noise. This includes field measurement methods, noise
modeling methods, and report preparation guidance.
Chapter 4 Federal Regulations and State Policies
Dune Palms Road Low Water Crossing Replacement Noise Study Report 16
Table 4-1.Activity Categories and Noise Abatement Criteria (23 CFR 772)
Activity
Category
Activity
Leq[h]1 Evaluation Location Description of Activities
A 57 Exterior Lands on which serenity and quiet are of extraordinary
significance and serve an important public need and where the
preservation of those qualities is essential if the area is to
continue to serve its intended purpose.
B2 67 Exterior Residential.
C2 67 Exterior Active sport areas, amphitheaters, auditoriums, campgrounds,
cemeteries, day care centers, hospitals, libraries, medical
facilities, parks, picnic areas, places of worship, playgrounds,
public meeting rooms, public or nonprofit institutional
structures, radio studios, recording studios, recreation areas,
Section 4(f) sites, schools, television studios, trails, and trail
crossings.
D 52 Interior Auditoriums, day care centers, hospitals, libraries, medical
facilities, places of worship, public meeting rooms, public or
nonprofit institutional structures, radio studios, recording
studios, schools, and television studios.
E 72 Exterior Hotels, motels, offices, restaurants/bars, and other developed
lands, properties, or activities not included in A–D or F.
F Agriculture, airports, bus yards, emergency services,
industrial, logging, maintenance facilities, manufacturing,
mining, rail yards, retail facilities, shipyards, utilities (water
resources, water treatment, electrical), and warehousing.
G Undeveloped lands that are not permitted.
1 The Leq(h) activity criteria values are for impact determination only and are not design standards for noise
abatement measures. All values are A-weighted decibels (dBA).
2 Includes undeveloped lands permitted for this activity category.
4.2. State Regulations and Policies
4.2.1. California Environmental Quality Act (CEQA)
Noise analysis under the California Environmental Quality Act (CEQA) may be required
regardless of whether or not the project is a Type I project. The CEQA noise analysis is
completely independent of the 23 CFR 772 analysis done for NEPA. Under CEQA, the
baseline noise level is compared to the build noise level. The assessment entails looking
at the setting of the noise impact and then how large or perceptible any noise increase
would be in the given area. Key considerations include: the uniqueness of the setting, the
sensitive nature of the noise receptors, the magnitude of the noise increase, the number of
residences affected, and the absolute noise level
Chapter 4 Federal Regulations and State Policies
Dune Palms Road Low Water Crossing Replacement Noise Study Report 17
The significance of noise impacts under CEQA are addressed in the environmental
document rather than the NSR. Even though the NSR (or noise technical memorandum)
does not specifically evaluate the significance of noise impacts under CEQA, it must
contain the technical information that is needed to make that determination in the
environmental document.
4.2.2. Section 216 of the California Streets and Highways Code
Section 216 of the California Streets and Highways Code relates to the noise effects of a
proposed freeway project on public and private elementary and secondary schools.
Under this code, a noise impact occurs if, as a result of a proposed freeway project, noise
levels exceed 52 dBA-Leq(h) in the interior of public or private elementary or secondary
classrooms, libraries, multipurpose rooms, or spaces. This requirement does not replace
the “approach or exceed” NAC criterion for FHWA Activity Category E for classroom
interiors, but it is a requirement that must be addressed in addition to the requirements of
23 CFR 772.
If a project results in a noise impact under this code, noise abatement must be provided to
reduce classroom noise to a level that is at or below 52 dBA-Leq(h). If the noise levels
generated from freeway and roadway sources exceed 52 dBA-L eq(h) prior to the
construction of the proposed freeway project, then noise abatement must be provided to
reduce the noise to the level that existed prior to construction of the project.
Dune Palms Road Low Water Crossing Replacement Noise Study Report 18
Chapter 5. Study Methods and Procedures
5.1. Methods for Identifying Land Uses and Selecting Noise
Measurement and Modeling Receiver Locations
A field investigation was conducted to identify land uses that could be subject to traffic
and construction noise impacts from the proposed project. Existing land uses in the
project area were categorized by land use type and Activity Category as defined in Table
4-1, and the extent of frequent human use. As stated in the Protocol, noise abatement is
only considered where frequent human use occurs and where a lowered noise level would
be of benefit. Although all land uses are evaluated in this analysis, the focus is on
locations of frequent human use that would benefit from a lowered noise level.
Accordingly, this impact analysis focuses on locations with defined outdoor activity
areas, such as residential backyards and common use areas at multi-family residences.
The geometry of the project relative to nearby existing and planned land uses was also
identified.
Short-term measurement locations were selected to represent each major developed area
within the project area. Also, short-term measurement locations were selected to serve as
representative modeling locations.
5.2. Field Measurement Procedures
A field noise study was conducted in accordance with recommended procedures in TeNS.
The following is a summary of the procedures used to collect short-term and long term
sound level data.
5.2.1. Short-Term Measurements
Short-term monitoring was conducted at three locations on Tuesday, April 7, 2015, using
a Bruel & Kjaer Model BK2238 Precision Type 1 sound level meters (serial numbers
2160297). The calibration of the meter was checked before and after the measurement
using a Bruel & Kjaer Model BK4230 calibrator (serial number 1351753). Measurements
were taken over a 15-minute period at each site. Short-term monitoring was conducted at
Activity Category B land uses. The short-term measurement locations are identified in
Figure 5-1.
Chapter 5 Study Methods and Procedures
Dune Palms Road Low Water Crossing Replacement Noise Study Report 19
Figure 5-1. Analysis Areas and Noise Monitoring Positions
During the short-term measurements, field staff attended each meter. Minute-to-minute
Leq values collected during the measurement period (typically 15 minutes in duration)
were logged manually, and dominant noise sources observed during each individual 1-
minute period were also identified and logged. Using this approach, those minutes when
traffic noise was observed to be a dominant contributor to noise levels at a given
measurement location could be distinguished from one-minute noise levels where other
Chapter 5 Study Methods and Procedures
Dune Palms Road Low Water Crossing Replacement Noise Study Report 20
non-traffic noise sources (such as aircraft and lawn equipment) contributed significantly
to existing noise levels.
Traffic on Dune Palm Road was classified and counted during short-term noise
measurements. Vehicles were classified as automobiles, medium-duty trucks, or heavy-
duty trucks. An automobile was defined as a vehicle with two axles and four tires that
are designed primarily to carry passengers. Small vans and light trucks were included in
this category. Medium-duty trucks included all cargo vehicles with two axles and six
tires. Heavy-duty trucks included all vehicles with three or more axles. The posted
speed on Dune Palm Road ranged between 25 mph north of CVSC and 45 mph south of
CVSC.
5.2.2. Long -Term Measurements
Long-term monitoring was conducted at one location (LT-1 on Figure 5-1) using a
Larson Davis Model 720 Type 2 sound level meter (serial numbers 0514). The purpose
of these measurements was to identify variations in sound levels throughout the day. The
long-term sound level data was collected over a 24-hour periods, beginning Monday, July
18, 2016 and ending on Tuesday, July 19, 2016.
Long-term monitoring location LT-1 was located at the pool area of Dune Palms Mobile
Estates at 46400 Dune Palms Road on the east side Dune Palms Road, approximately 40
feet from the edge-of-pavement (refer to Figure 5-1). This is near the modeling site of
M1.
5.3. Traffic Noise Levels Prediction Methods
Traffic noise levels were predicted using the FHWA Traffic Noise Model Version 2.5
(TNM 2.5). (Use the current applicable model version.) TNM 2.5 is a computer model
based on two FHWA reports: FHWA-PD-96-009 and FHWA-PD-96-010 (FHWA 1998a,
1998b). Key inputs to the traffic noise model were the locations of roadways, traffic mix
and speed, shielding features (e.g., topography and buildings), noise barriers, ground
type, and receptors. Three-dimensional representations of these inputs were developed
using CAD drawings, aerials, and topographic contours provided by the Bengal
Engineering, Inc.
Traffic noise was evaluated under existing conditions, design-year no-project conditions,
and design-year conditions with the project alternative. Peak-hour traffic volumes,
vehicle classification percentages, and traffic speeds under existing and design-year
(2040) conditions were provided by Parsons Brinckerhoff (Traffic Analysis Report,
Chapter 5 Study Methods and Procedures
Dune Palms Road Low Water Crossing Replacement Noise Study Report 21
October 2015) and determined during 24-hour measurement for input into the traffic
noise model. The highest average traffic volumes on Dune Palms Road are predicted to
occur during the PM peak hour; therefore PM peak hour traffic volumes were used in the
model. Tables A-1 to A-3 in Appendix A summarize the traffic volumes and
assumptions used for modeling existing and design-year conditions with and without the
project alternative.
To validate the accuracy of the model calculations, TNM 2.5 was used to compare
measured traffic noise levels to modeled noise levels at field measurement locations. For
each receptor, traffic volumes counted during the short-term measurement periods were
normalized to 1-hour volumes. These normalized volumes were assigned to the
corresponding project area roadways to simulate the noise source strength at the
roadways during the actual measurement period. Modeled and measured sound levels
were then compared to determine the accuracy of the model and if additional adjustment
of the model was necessary.
5.4. Methods for Identifying Traffic Noise Impacts and
Consideration of Abatement
Traffic noise impacts are considered to occur at receptor locations where predicted
design-year noise levels are 12 dB or more greater than existing noise levels, or where
predicted design-year noise levels approach or exceed the NAC for the applicable activity
category. Where traffic noise impacts are identified, noise abatement must be considered
for reasonableness and feasibility as required by 23 CFR 772 and the Protocol.
According to the Protocol, abatement measures are considered acoustically feasible if a
minimum noise reduction of 5 dB at impacted receptor locations is predicted with
implementation of the abatement measures. In addition, barriers should be designed to
intercept the line-of-sight from the exhaust stack of a truck to the first tier of receptors, as
required by the Highway Design Manual, Chapter 1100. Other factors that affect
feasibility include topography, access requirements for driveways and ramps, presence of
local cross streets, utility conflicts, other noise sources in the area, and safety
considerations.
The overall reasonableness of noise abatement is determined by the following three
factors:
x The noise reduction design goal.
Chapter 5 Study Methods and Procedures
Dune Palms Road Low Water Crossing Replacement Noise Study Report 22
x The cost of noise abatement.
x The viewpoints of benefited receptors (including property owners and
residents of the benefited receptors).
The Caltrans’ acoustical design goal is that a barrier must be predicted to provide at least
7 dB of noise reduction at one benefited receptor. This design goal applies to any receptor
and is not limited to impacted receptors.
The Protocol defines the procedure for assessing reasonableness of noise barriers from a
cost perspective. Based on 2014 construction costs an allowance of $80,000 is provided
for each benefited receptor (i.e., receptors that receive at least 5 dB of noise reduction
from a noise barrier). The total allowance for each barrier is calculated by multiplying
the number of benefited receptors by $80,000. The allowance should be adjusted annually
based on the published Caltrans Construction Price Index (CPI) and a base 2011
allowance of $55,000. If the estimated construction cost of a barrier is less than the total
calculated allowance for the barrier, the barrier is considered reasonable from a cost
perspective. The viewpoints of benefits receptors are determined by a survey that is
typically conducted after completion of the noise study report. The process for
conducting the survey is described in detail in the Protocol.
The noise study report identifies traffic noise impacts and evaluates noise abatement for
acoustical feasibility. It also reports information that will be used in the reasonableness
analysis including if the 7 dB design goal reduction in noise can be achieved and the
abatement allowances. The noise study report does not make any conclusions regarding
reasonableness. The feasibility and reasonableness of noise abatement is reported in the
Noise Abatement Decision Report.
Dune Palms Road Low Water Crossing Replacement Noise Study Report 23
Chapter 6. Existing Noise Environment
6.1. Existing Land Uses
A field investigation was conducted to identify land uses that could be subject to traffic
and construction noise impacts from the proposed project. The following land uses were
identified in the project area:
x Single-family residences: Activity Category B
x Places of worship: Activity Category C (exterior), Activity Category D (interior)
x School: Activity Category C (exterior), Activity Category D (interior)
x Commercial retail uses: Activity Category F
Although all developed land uses are evaluated in this analysis, noise abatement is only
considered for areas of frequent human use that would benefit from a lowered noise level.
Accordingly, this impact analysis focuses on locations with defined outdoor activity
areas, such as residential backyards and common use areas at multi-family residences.
Land uses in the project area are identified in Figure 5-1.
x Area A:Located on the northeast side of Dune Palms Road between CVSC and
Westward Ho Drive. A mobile home park (Activity Category B) and a church
(Activity Category C-D) is located in this area. This area is generally flat.
Backyards face the street. A five to six foot tall wooden fence shields the residences
in this area. (Refer to Figure 5-1.)
x Area B:Located on the northwest side of Dune Palms Road between CVSC and
Westward Ho Drive. La Quinta High School (Activity Category C-D) is located in
this area. This area is generally flat. No sound barrier or topographical shielding
occurs between the roadway and the high school area. (Refer to Figure 5-1.)
x Area C - South of Coachella Valley Storm Water Channel (CVSC):No sensitive
receivers were found in this area. This area consist of commercial building and a
commercial zoned vacant lot.
Chapter 6 Existing Noise Environment
Dune Palms Road Low Water Crossing Replacement Noise Study Report 24
6.2. Noise Measurement Results
The existing noise environment in the project area is characterized below based on short-
and long-term noise monitoring that was conducted.
6.2.1. Short-Term Monitoring
Table 6-1 summarizes the results of the short-term noise monitoring conducted in the
project area.
Table 6-1. Summary of Short-Term Measurements
Position Address Area Land Uses Start
Time
Duration
(minutes)
Measured
Leq
Autos*Medium
Trucks*
Heavy
Trucks*
Observed
Speed
(mph)
ST-1 46300
Dune
Palms Rd
A Church 11:00
a.m.
15 59.4 119 4 0 35
ST-2 46400
Dune
Palms Rd
#58
A Residential 11:30
a.m.
15 56.0 120 3 0 35
ST-3 46500
Dune
Palms Rd
A Residential 12:00
a.m.
15 67.4 155 9 0 35-45
Note:Refer to Figure 5-1 for measurement locations and boundaries of each area.
*Traffic total for both directions
No noise monitoring was conducted in Area B because access to the school grounds were
not permitted; however, two modeling locations were added during modeling. Also, no
noise monitoring was conducted in Area South of CVSC where the commercial retail lots
are located. Since there is no noise abatement criterion for this land use, monitoring in
this area is less important than other areas.
6.2.2. Long-Term Monitoring
The long-term sound level data was collected over a 24-hour periods, beginning Monday,
July 18, 2016 and ending on Tuesday, July 19, 2016.
Long-term monitoring location LT-1 was located at the residence at 46400 Dune Palms
Road on the east side of Dune Palms Road, approximately 40 feet from Dune Palms Road
edge-of-pavement (refer to Figure 5-1). This is near the modeling Site M1. The loudest-
hour sound level measured was 62.3 dBA Leq(h) during the 5:00 p.m. hour. Table 6-2
and Figure 6-1 summarize the results of the long-term monitoring.
Chapter 6 Existing Noise Environment
Dune Palms Road Low Water Crossing Replacement Noise Study Report 25
Table 6-2. Summary of Long-Term Monitoring at Location LT-1
Hour Beginning Hourly (dBA Leq[h])Difference from
Loudest Hour (dB)
12:00 a.m.45.1 -17.2
1:00 a.m.44.6 -17.7
2:00 a.m.43.6 -18.7
3:00 a.m.44.1 -18.2
4:00 a.m.46.8 -15.5
5:00 a.m.48.3 -14
6:00 a.m.59.6 -2.7
7:00 a.m.60.1 -2.2
8:00 a.m.61.5 -0.8
9:00 a.m.61.8 -0.5
10:00 a.m.57.1 -5.2
11:00 a.m.59.3 -3
12:00 p.m.60.8 -1.5
1:00 p.m.59.6 -2.7
2:00 p.m.58.1 -4.2
3:00 p.m.58.1 -4.2
4:00 p.m.61.1 -1.2
5:00 p.m.62.3 0
6:00 p.m.62.1 -0.2
7:00 p.m.55 -7.3
8:00 p.m.53.2 -9.1
9:00 p.m.52.2 -10.1
10:00 p.m.47.7 -14.6
11:00 p.m.46.3 -17.3
Note:Worst noise hour noise level is bolded.
Chapter 6 Existing Noise Environment
Dune Palms Road Low Water Crossing Replacement Noise Study Report 26
Figure 6-1. Long-Term Monitoring at Location LT-1, July 18-19, 2016
TNM 2.5 was used to compare measured traffic noise levels to modeled noise levels at
field measurement locations. Table 6-2 compares measured and modeled noise levels at
each measurement location (see Figure 5-1).The predicted sound levels are within 1 dB
of the measured sound levels for ST-1 and ST-2 and are, therefore, considered to be in
reasonable agreement with the measured sound levels. Measurement site ST-3 was 3.2
dBA lower than what was measured.The existing roadway within the riverbed is graded
with vertical grooves to assist with drainage. However, the grooves create a rough texture
on the roadway which increases the tire noise. A +3.2 K-factor will be added to the
existing, No Build and Build option.
Table 6-3. Comparison of Measured to Predicted
Sound Levels in the TNM Model
Measurement
Position
Measured Sound
Level (dBA)
Predicted Sound
Level (dBA)
Measured minus
Predicted (dB)
ST-1 59.4 59.4 0.0
ST-2 56.0 55.9 +0.1
ST-3 67.4 64.2 + 3.2
Table B-1 in Appendix B presents existing noise levels at each receptor.
35
40
45
50
55
60
65
70
75
80
85
90
12:00AM1:00AM2:00AM3:00AM4:00AM5:00AM6:00AM7:00AM8:00AM9:00AM10:00AM11:00AM12:00PM1:00PM2:00PM3:00PM4:00PM5:00PM6:00PM7:00PM8:00PM9:00PM10:00PM11:00PM Leq
Lmax
L( 1)
L(10)
L(50)
L(90)
Dune Palms Road Low Water Crossing Replacement Noise Study Report 27
Chapter 7. Future Noise Environment,
Impacts, and Considered
Abatement
7.1. Future Noise Environment and Impacts
Table B-1 in Appendix B summarizes the traffic noise modeling results for existing
conditions and design-year conditions with and without the project. Predicted design-
year traffic noise levels with the project are compared to existing conditions and to
design-year no-project conditions. The comparison to existing conditions is included in
the analysis to identify traffic noise impacts as defined under 23 CFR 772. The
comparison to no-project conditions indicates the direct effect of the project.
As stated in the TeNS, modeling results are rounded to the nearest decibel before
comparisons are made. In some cases, this can result in relative changes that may not
appear intuitive. An example would be a comparison between calculated sound levels of
64.4 and 64.5 dBA. The difference between these two values is 0.1 dB. However, after
rounding, the difference is reported as 1 dB.
Measurement site ST-1 represents modeling site M3, measurement site ST-2 represents
modeling sites M1, M2, and M4, and measurement site ST-3 represents modeling site
M5. Modeling results in Appendix B, Table B-1, indicate the following:
Area A
The traffic noise modeling results in Table B-1 indicate that traffic noise levels at the
church and residences in Area A are predicted to be in the range of 60 to 64 dBA Leq(h)
in the design-year with Project. The results also indicate that the increase in noise
between existing conditions and the design-year with Project is predicted to be 1 to 8dB.
The property represented by ST-3 was determined to be a property acquisition due to
additional land needed for the Project; therefore, no results were determined for this site
for the design-year with Project. Because the predicted noise levels in the design-year are
not predicted to approach or exceed the noise abatement criterion (67 dBA Leq[h]) or
result in a substantial increase in noise, no traffic noise impacts are predicted in Area A.
Because the church has an interior noise abatement criterion in addition to the exterior
criterion, interior noise must be considered at the church as well. From Table 6 in the
FHWA Highway Traffic Noise Analysis and Abatement Guidance document, the
Chapter 7 Future Noise Environment, Impacts, and Considered Abatement
Dune Palms Road Low Water Crossing Replacement Noise Study Report 28
building noise reduction factor for standard construction with ordinary windows closed is
20 dB. The interior noise level in the church in the design-year with Project is therefore
predicted to be 44 dBA Leq(h). Because this predicted design-year with Project noise
level does not exceed the interior NAC of 52 dBA Leq(h), no interior traffic noise
impacts are predicted at the church.
Area B
The traffic noise modeling results in Table B-1 indicate that traffic noise levels at school
in Area B are predicted to range between 60 and 61 dBA Leq(h) in the design-year with
Project. The results also indicate that the increase in noise between existing conditions
and the design-year is predicted to be 5 to 6 dB. Because the predicted noise levels in the
design-year are not predicted to approach or exceed the noise abatement criterion (67
dBA Leq[h]) or result in a substantial increase in noise, no traffic noise impacts are
predicted in Area B.
Because the school has an interior noise abatement criterion in addition to the exterior
criterion, interior noise must be considered at the school as well. From Table 6 in the
FHWA Highway Traffic Noise Analysis and Abatement Guidance document, the
building noise reduction factor for standard construction with ordinary windows closed is
20 dB. The interior noise level in the school in the design-year with Project is therefore
predicted to range from 40 to 41dBA Leq(h). Because this predicted design-year with
Project noise level does not exceed the interior NAC of 52 dBA Leq(h), no interior traffic
noise impacts are predicted at the school.
Area C
The existing traffic noise in Area C is predicted to be 63 dBA Leq(h). The level at the
vacant lot in Area C is predicted to be 69 dBA Leq(h) in the design-year with Project.
The results also indicate that the increase in noise between existing conditions and the
design-year with Project is predicted to be 6 dB. Because the noise levels in the design-
year with Project are not predicted to approach or exceed the noise abatement criterion
(72 dBA Leq[h]) or result in a substantial increase in noise, no traffic noise impacts are
predicted in Area C.
7.2. Preliminary Noise Abatement Analysis
Noise abatement is considered where noise impacts are predicted in areas of frequent
human use that would benefit from a lowered noise level. According to 23 CFR
Chapter 7 Future Noise Environment, Impacts, and Considered Abatement
Dune Palms Road Low Water Crossing Replacement Noise Study Report 29
772(13)(c) and 772(15)(c), federal funding may be used for the following abatement
measures:
x Construction of noise barriers, including acquisition of property rights, either
within or outside the highway right-of-way.
x Traffic management measures including, but not limited to, traffic control devices
and signing for prohibition of certain vehicle types, time-use restrictions for
certain vehicle types, modified speed limits, and exclusive lane designations.
x Alteration of horizontal and vertical alignments.
x Acquisition of real property or interests therein (predominantly unimproved
property) to serve as a buffer zone to preempt development which would be
adversely impacted by traffic noise.
x Noise insulation of Activity Category D land use facilities listed in Table 1. Post-
installation maintenance and operational costs for noise insulation are not eligible
for Federal-aid funding.
7.2.1. Area A
No traffic noise impacts are predicted for Area A. Accordingly, noise abatement does not
need to be considered in this area.
7.2.2. Area B
No traffic noise impacts are predicted for Area B. Accordingly, noise abatement does not
need to be considered in this area.
7.2.3. Area C
No traffic noise impacts are predicted for Area C. Accordingly, noise abatement does not
need to be considered in this area.
Dune Palms Road Low Water Crossing Replacement Noise Study Report 30
Chapter 8. Construction Noise
During construction of the project, noise from construction activities may intermittently
dominate the noise environment in the immediate area of construction. To minimize the
construction generated noise impact the standard specification 14-8.02 and SSP 14-8.02
or by La Quinta’s Municipal Code, Section 6.08.050 and the General Standard
Conditions whichever one is more stringent will be followed. The General Standard
Conditions, “Noise Control,” which states the following:
It is a nuisance and it is unlawful, for any person to be engaged or employed, or
for any person to cause any other person to be engaged or employed, in any work
of construction, erection, alteration, repair, addition to, or improvement to realty,
except between the hours set forth as follows:
October 1th through April 30th Monday – Friday 7:00 AM – 5:30 PM
Saturday 8:00 AM – 5:00 PM
Sunday & Holidays None
May 1st through September 30th Monday – Friday 6:00 AM – 7:00 PM
Saturday 8:00 AM – 5:00 PM
Sunday & Holidays None
Equip an internal combustion engine with the manufacturer-recommended
muffler. Do not operate an internal combustion engine on the job site without the
appropriate muffler.
Table 8-1 summarizes noise levels produced by construction equipment that is commonly
used on roadway construction projects. Construction equipment is expected to generate
noise levels ranging from 70 to 90 dB at a distance of 50 feet, and noise produced by
construction equipment would be reduced over distance at a rate of about 6 dB per
doubling of distance.
Chapter 9 References
Dune Palms Road Low Water Crossing Replacement Noise Study Report 31
Table 8-1. Construction Equipment Noise
Equipment Maximum Noise Level (dBA at 50
feet)
Scrapers 89
Bulldozers 85
Heavy Trucks 88
Backhoe 80
Pneumatic Tools 85
Concrete Pump 82
Source:Federal Transit Administration, 2006.See also:
http://www.fhwa.dot.gov/environment/noise/construction_noise/handbook/handbook09.cfm
No adverse noise impacts from construction are anticipated because construction would
be conducted in accordance with La Quinta’s Municipal Code, Section 6.08.050 and the
General Standard Conditions. Construction noise would be short-term, intermittent, and
overshadowed by local traffic noise.
Chapter 9 References
Dune Palms Road Low Water Crossing Replacement Noise Study Report 32
Chapter 9. References
Caltrans. 2013. Technical Noise Supplement. September. Sacramento, CA:
Environmental Program, Noise, Air Quality, and Hazardous Waste Management
Office. Sacramento, CA. Available:
(http://www.dot.ca.gov/hq/env/noise/pub/TeNS_Sept_2013B.pdf).
———. 2011. Traffic Noise Analysis Protocol for New Highway Construction,
Reconstruction, and Retrofit Barrier Projects. May. Sacramento, CA. Available:
(http://www.dot.ca.gov/hq/env/noise/pub/ca_tnap_may2011.pdf).
Caltrans. 2013. Transportation and Construction Vibration Guidance Manual.
September. Sacramento, CA: Environmental Program, Noise, Air Quality, and
Hazardous Waste Management Office. Sacramento, CA. Available:
(http://www.dot.ca.gov/hq/env/noise/pub/TCVGM_Sep13_FINAL.pdf)
Federal Highway Administration. 2011. Highway Traffic Noise: Analysis and
Abatement Guidance. December. Washington D.C. FHWA-HEP-10-025.
Available:
(http://www.fhwa.dot.gov/environment/noise/regulations_and_guidance/analysis_
and_abatement_guidance/revguidance.pdf)
———. 1998a. FHWA Traffic Noise Model, Version 1.0 User’s
Guide. January. FHWA-PD-96-009. Washington D.C.
———. 1998b. FHWA Traffic Noise Model, Version 1.0. February. FHWA-PD-96-
010. Washington D.C.
———. 2006. Roadway Construction Noise Model. February, 15, 2006. Available:
(http://www.fhwa.dot.gov/environment/noise/construction_noise/rcnm/).
Federal Transit Administration. 2006.Transit Noise and Vibration Impact Assessment.
(DOT-T-95-16.)Office of Planning, Washington, DC. Prepared by Harris Miller
Miller & Hanson, Inc. Burlington, MA.
Dune Palms Road Low Water Crossing Replacement Noise Study Report 33
Appendix A Traffic Data
Dune Palms Road Low Water Crossing Replacement Noise Study Report 34
Table A-1. Traffic Data for Existing Conditions
Segment Number
of Lanes
Total
Volume PM
Peak Hour
Volume
Auto Medium Trucks Heavy Trucks Speed
(A/MT/HT
)%Volume %Volume % Volume
Mainline
NB Dune Palms
Road Between Hwy 111 and CVSC 1 299 94.8%283 5.0%15 0.2%1 45/45/45
NB Dune Palms
Road
Between CVSC and
Westward Ho Drive 1 299 94.8%283 5.0%15 0.2%1 25/25/25
SB Dune Palms
Road Between Hwy 111 and CVSC 2 305 97.8%298 2.0%6 0.2%1 45/45/45
SB Dune Palms
Road
CVSC and Westward Ho
Drive 1 305 97.8%298 2.0%6 0.2%1 25/25/25
Dune Palms Road Low Water Crossing Replacement Noise Study Report 35
Table A-2. Traffic Data for Design Year No-Project Conditions
Segment Number
of Lanes
Total
Volume PM
Peak Hour
Volume
Auto Medium Trucks Heavy Trucks
Speed%Volume %Volume % Volume
Mainline
NB Dune Palms
Road Between Hwy 111 and CVSC 1 1165 94.8%1105 5.0%58 0.2%2 45/45/45
NB Dune Palms
Road
Between CVSC and
Westward Ho Drive 1 1165 94.8%1105 5.0%58 0.2%2 25/25/25
SB Dune Palms
Road Between Hwy 111 and CVSC 2 1294 97.8%1266 2.0%26 0.2%3 45/45/45
SB Dune Palms
Road
CVSC and Westward Ho
Drive 1 1294 97.8%1266 2.0%26 0.2%3 25/25/25
Dune Palms Road Low Water Crossing Replacement Noise Study Report 36
Table A-3. Traffic Data for Design Year with Project Conditions
Segment Number
of Lanes
Total
Volume PM
Peak Hour
Volume
Auto Medium Trucks Heavy Trucks
Speed%Volume %Volume % Volume
Mainline
NB Dune Palms
Road Between Hwy 111 and CVSC 2 1165 94.8%1105 5.0%58 0.2%2 45/45/45
NB Dune Palms
Road
Between CVSC and
Westward Ho Drive 2 1165 94.8%1105 5.0%58 0.2%2 25/25/25
SB Dune Palms
Road Between Hwy 111 and CVSC 2 1294 97.8%1266 2.0%26 0.2%3 45/45/45
SB Dune Palms
Road
CVSC and Westward Ho
Drive 2 1294 97.8%1266 2.0%26 0.2%3 25/25/25
Table A-4. Traffic Data for Vaidation Files
Site Roadway Auto Medium Trucks Heavy Trucks
ST-1 NB Dune Palm Road 236 4 0
SB Dune Palm Road 240 12 0
ST-2 NB Dune Palm Road 252 8 0
SB Dune Palm Road 228 4 0
ST-3 NB Dune Palm Road 268 28 0
SB Dune Palm Road 352 8 0
Dune Palms Road Low Water Crossing Replacement Noise Study Report 37
Appendix B Predicted Future Noise Levels
and Noise Barrier Analysis
Dune Palms Road Low Water Crossing Replacement Noise Study Report 38
Table B-1. Predicted Future Noise and Barrier Analysis
ReceptorI.D.AreaBarrierI.D.LandUseNumberofDwellingUnitsAddressExistingNoiseLevelLeq(h),dBASR-26 Future Worst Hour Noise Levels - Leq(h), dBA
DesignYearNoiseLevelwithoutProjectLeq(h),dBADesignYearNoiseLevelwithProjectLeq(h),dBADesignYearNoiseLevelwithoutProjectminusExistingConditionsLeq(h),dBADesignYearNoiseLevelwithProjectMinusNoProjectConditionsLeq(h),dBAActivityCategory(NAC)ImpactTypeNoise Prediction with Barrier, Barrier Insertion Loss (I.L.), and
Number of Benefited Receptors (NBR)
6 feet 8 feet 10 feet 12 feet 14 feet 16 feet
Leq(h)I.L.NBRLeq(h)I.L.NBRLeq(h)I.L.NBRLeq(h)I.L.NBRLeq(h)I.L.NBRLeq(h)I.L.NBRST-1 A -Church 1 46300 Dune
Palms Drive 57 63 64 6 1 C (67) None – – – – – – – – – – – – – – – – – –
M2 A - Residential 2 46400 Dune
Palms Drive 53 59 60 6 1 B (67) None – – – – – – – – – – – – – – – – – –
ST-2 A NB-1 Residential 2 46400 Dune
Palms Drive 56 62 63 6 1 B (67) None – – – – – – – – – – – – – – – – – –
M1 A NB-1 Residential 2 46400 Dune
Palms Drive 53 59 61 6 2 B (67) None – – – – – – – – – – – – – – – – – –
ST-3^A NB-1 Residential 2 46400 Dune
Palms Drive 65 71 -6 -PROPERTY ACQUISITION
M5 A NB-1 Residential 1 46400 Dune
Palms Drive 60 66 64 6 -2 B (67) None – – – – – – – – – – – – – – – – – –
M3 B -School None
79255
Westward Ho
Drive
55 61 61 6 0 C (67) None – – – – – – – – – – – – – – – – – –
M4 B -School None
79255
Westward Ho
Drive
55 60 60 5 0 C (67) None – – – – – – – – – – – – – – – – – –
M6 C -Vacant None Vacant 63 69 69 6 0 E (72) None
Note: All NAC are exterior unless note. A/E= Future noise conditions approach or exceed the Noise Abatement Criteria; SI = Substantial Increase^ Property Acquisition.
Dune Palms Road Low Water Crossing Replacement Noise Study Report 39
Appendix C Supplemental Data
Site 1
Site 2
Site 3
1 / 1
ADDENDUM TO TRAFFIC ANALYSIS REPORT
From:Joe De La Garza, WSP | Parsons Brinckerhoff
Date:January 13, 2016
Project Name:Dune Palms Road Crossing Replacement Project in City of La Quinta
BLRKS 5433 (014)
Comments were received from Caltrans in December 2015. Per Caltrans’ request, these comments will be part of
an addendum to the traffic study and are meant to clarify information, instead of introducing new analysis or
changes to the October 21, 2015 Traffic Analysis Report.
The following are responses to the comments:
How were truck counts incorporated into Synchro analysis?
Truck counts were collected for the roadway segment of Dune Palms Road over the Low Water Crossing.
Typically, peak hour truck counts are not collected for the intersections unless there is a specific reason to believe
that the truck traffic is great enough to affect the traffic operations. Synchro uses a standard truck percentage of
2% for the operational analysis and that is what was included in this traffic analysis. The reported volume of
trucks is not significant enough to affect operations and therefore was not specifically included in the analysis.
Was post-processing procedure performed to balance traffic volumes?
No post processing was done to balance the traffic volumes between the two study intersections. The peak hour
volumes that were collected for existing condition constituted the worst-case for each movement and typically no
additional volume balancing would be done.
Horizon Year volumes were extracted from the General Plan. Please discuss the source and procedures
performed to forecast Horizon Year volumes. Was a particular travel demand modeling used?
Per the City of La Quinta’s General Plan – The General Plan used a La Quinta focused travel demand model
called the La Quinta Traffic Analysis Model (LQTAM) which was based on the Year 2008 Riverside Traffic
Analysis Model (RivTAM). The procedures that were used to prepare the forecast Horizon Year volumes are
documented in City of La Quinta General Plan Circulation Element Update Traffic Impact Analysis, May 14, 2012.
Traffic counts and LOS analysis are missing for project Opening Year. Please provide explanation to why
Opening Year data and analysis are omitted.
No opening year analysis was done for the project since the future buildout (2040) as provided by the General
Plan Horizon Year provides a conservative evaluation of the intersections. The level of service for the
intersections at the worst case scenario is acceptable per the City’s General Plan.
If you have any questions or comments regarding this analysis, please let me know.
Thank you,
Joe De La Garza
Senior Traffic Engineer
DUNE PALMS ROAD LOW WATER CROSSING REPLACEMENT
PROJECT
CITY OF LA QUINTA
RIVERSIDE COUNTY, CALIFORNIA
Traffic Analysis Report
October 2015
Prepared for:
City of La Quinta
Federal Project Number BLRKS-5433(014)
Prepared by:
Page 1
1.Introduction
Project Purpose
The purpose of the project is to replace the existing low-water crossing spanning the Coachella Valley
Storm Water Channel (CVSC) at Dune Palms Road with an all-weather access. The proposed
improvements will accomplish the following in the project area:
1.Provide safe access across the CVSC (Whitewater River) during all-weather events
2.Provide reliable route for emergency vehicles, motorists, pedestrians, and bicyclists
3.Achieve the City’s General Plan goals for the corridor
Project Need
Dune Palms Road serves a vital access for emergency services within the project area, as well as for La
Quinta High, John Glenn Middle and Amelia Earhart Elementary Schools. It also provides connectivity of
the city residential development north of the Channel with the Highway 111 commercial corridor
located south of the CVSC. (Please see attached Vicinity and Location Maps)
The CVSC conveys storm water runoff from the surrounding mountains as well as developed areas
within the Coachella Valley. The elevation of the existing Dune Palms Road low-water crossing causes it
to flood during minor rain events (2-year frequency) and results in full street closure and detour of both
vehicle and pedestrian traffic. In the interest of public health and safety, and in response to community
concerns regarding frequent closures of the low-water crossing, the City of La Quinta has determined
that replacement of the low-water crossing with a new bridge is needed to ensure that all-weather
access is maintained. The Dune Palms Road low-water crossing is the last remaining low-water crossing
of the CVSC within the City.
Project Description
Existing Conditions. The existing roadway crosses the CVSWC at the channel grade. The roadway width is
68 feet at the crossing, and consists of one northbound and two southbound through lanes, eight foot
wide walkway area along the western edge, and an eight foot shoulder along the eastern edge of the
road; and no median. The existing roadway approach south of the crossing consists of one northbound
and two southbound through lanes. The northern roadway approach consists of one through lanes in
each direction. The transition from one to two lanes in the southbound direction occurs at the midpoint
of the channel crossing. Dune Palms Road approximately one-quarter mile north of the channel low-
water crossing and just south of the project limits is a four lane roadway with a median. The roadway
section just north of the crossing will be widened as part of an approved City project. The project was
originally approved with a Mitigated Negative Declaration under CEQA in April 2010. The PS&E for the
project was 90% complete.
Page 2
Proposed Improvements. The project proposes to remove the existing low-water crossing of Dune Palms
Road at the CVSC in the City of La Quinta, Riverside County. The crossing will be replaced with a 480 feet
long and 86 feet wide four-span bridge. The bridge typical section consists of six-foot sidewalk on both
sides of the bridge, two (2) eight-foot outside shoulders also serving as bike/golf cart lanes, a 10 foot
raised median, two (2) eleven-foot travel lanes, and two (2) twelve-foot travel lanes.
The proposed configuration will be consistent with the existing four lane roadway section to the south,
and the City’s current improvement project to the north (City Project Number 2009-04), which will
widen Dune Palms Road from two to four lanes with a median and left turn lanes.
The proposed improvements will include a reconstruction of the north and south bridge approaches to
accommodate the significant raised profile of the roadway. In order to match the roadway section on
the south side of the bridge, the project’s construction limits will be extended to 239 feet of Highway
111. On the north side of the bridge, the project construction limits will be extended to include a vacant
lot immediately north of the project limits. The vacant lot is owned by the City and will be offered by the
City in the bidding documents to be used for storage and construction staging by the contractor for the
construction of this project.
As a part of the bridge construction, concrete slope protection will be installed along the north side of
the channel. Additionally, minor removal and replacement of slope protection will be required on the
south side of channel west of the proposed bridge and extension of slope protection approximately 300
feet downstream of the proposed bridge. The slope protection is needed for scour countermeasures as
required by the Coachella Valley Water District (CVWD), who is responsible for the operations and
maintenance of the CVSC. As a result of the proposed cast-in-place drilled shaft bridge construction,
scour protection within the bottom of the channel will not be required.
The project will also include the following additional improvements:
• Railing Architectural treatment. The bridge design will incorporate railing architectural
treatment as required by the City’s standard design.
• Integration of a regional Bike/Pedestrian/NEV corridor (CV Link). The Coachella Valley
Association of Governments (CVAG) and the communities within the Coachella Valley are
working together on the implementation of a regional Bike/Pedestrian/NEV corridor (CV Link)
along Whitewater River and Coachella Valley Storm Water Channel. The project design will be
consistent with these plans by allowing for the integration of a trail under crossing within the
southern slope protection, which also includes a trail connector to the pedestrian and bike
facilities proposed along Dune Palms Road in the project area.
• Utility Relocation. The project will also require utility relocations for overhead electrical
distribution lines (Imperial Irrigation District facility), adjustment to both water valve can and
lids and the manhole covers, minor 12” ductile iron pipe water main relocations at each bridge
abutment, and relocation of both a 12” and 18” sewer line at the northern bridge abutment.
Page 3
Right-of-Way Requirements. The project will require right-of-way acquisition on the northeast and
southeast corners of the proposed bridge. The existing development at the northeast corner of the
proposed bridge consists of a Mobile Home Park with one single family home. Some of the mobile
homes adjacent to the Dune Palms Road are encroaching within the street right of way. The project may
require the acquisition of the single-family residence and relocation of two mobile homes residents. The
project will be designed to avoid and minimize relocation impacts of the mobile homes. At the
southeast corner of the crossing, the existing parcel is currently an undeveloped commercial parcel.
Acquisition for the vacant parcel will consist of a strip taking parallel with Dune Palms Road.
Construction of Temporary Bypass. The existing roadway will be modified to construct a temporary
bypass road. The temporary bypass will allow for staged construction of the bridge, and maintaining
vehicle and pedestrian access at all times. Temporary and short term access impact may occur during
construction, and will require coordination with property owners, the public, and other stakeholders.
Traffic Study
This report provides traffic analysis of Dune Palms Road at the project location and at the adjacent
intersections of Dune Palms at Highway 111 and Dune Palms Road at Westward Ho
Drive/Blackhawk Way. The analysis includes existing and future conditions with and without the project.
Although traffic operations in the vicinity of the crossing are degraded when Dune Palms Road is closed
due to weather events, and traffic is diverted to nearby roads and intersections, this traffic study focuses
on the adjacent intersections since they are directly affected by the improvements on Dune Palms Road.
Page 4
2.Study Area
The study area for this project includes the segment of Dune Palms Road between Highway 111 and
Westward Ho Drive/Blackhawk Way. The study also includes the two signalized intersections on either
side of this segment of Dune Palms Road that is being reconstructed. The study intersections and
segment are listed below and shown in Figure 1.
1.Dune Palms Road and Westward Ho Drive/Blackhawk Way
2.Dune Palms Road and Highway 111
3.Study Scenarios
This report presents the analysis of the following three study scenarios:
x Existing Conditions – operation of the intersections and roadway segment with existing traffic
volumes
x Future 2040 No-Build Conditions – operation of the intersections and roadway segment with
future traffic volumes and existing roadway geometrics (i.e. number of lanes)
x Future 2040 Build Conditions – operation of the intersections and roadway segment with future
traffic volumes and proposed roadway reconstruction geometrics
Figure 1: Dune Palms Road Project Location and Study Area
Page 5
4.Study Analysis Methodology
Street system operating conditions are typically described in terms of “level of service.” Level of service
is a report-card scale used to indicate the quality of traffic flow on roadway segments and at
intersections. Level of service (LOS) ranges from LOS A (free flow, little congestion) to LOS F (forced flow,
extreme congestion). A more detailed description of the concepts described in this section is provided in
Appendix A of this document. The following methods are used in this study.
Roadway Segment Capacity Analysis
The City of La Quinta has published daily traffic volume standards for roadways within its jurisdiction in
the Circulation Element of the General Plan, adopted by the City on 2/19/2013. To determine service
levels on study area roadway segments, we compared the appropriate average daily traffic thresholds
for level of service to the daily capacity of the study area roadway segments, and the existing and future
volumes in the study area. The thresholds for determining level of service used in this analysis are
shown in Appendix A.
Intersection Capacity Analysis
The analysis of peak hour intersection performance was conducted using the SYNCHRO analysis
software program, which uses methodologies defined in the 2000 Highway Capacity Manual (HCM) to
calculate results. Level of service (LOS) for intersections is determined by control delay. Control delay is
defined as the total elapsed time from when a vehicle stops at the end of a queue to the time the
vehicle departs from the stop line. The total elapsed time includes the time required for the vehicle to
travel from the last-in-queue position to the first-in-queue position, including deceleration of vehicles
from free-flow speed to the speed of vehicles in the queue. The HCM analysis methodology for
evaluating signalized intersections is based on the “operational analysis” procedure. This technique
uses 1,900 passenger cars per hour of green per lane (pcphgpl) as the maximum saturation flow of a
single lane at an intersection. This saturation flow rate is adjusted to account for lane width, on-street
parking, conflicting pedestrian flow, traffic composition, (e.g., the percentage of vehicles that are trucks)
and shared lane movements (e.g., through and right-turn movements from the same lane). Average
control delay is calculated by taking a volume-weighted average of all the delays for all vehicles entering
the intersection. The intersection analysis focuses on the intersection peak hour during a weekday.
Appendix A lists the HCM delay/LOS criteria for signalized intersections.
General Plan’s Concept LOS
The City of La Quinta has established LOS D as the threshold for acceptable operating conditions;
therefore all roadways and intersections operating at LOS D or better are acceptable. Roadways and
intersections that operate at LOS E or F are considered deficient.
Page 6
5.Analysis Results
5.1 Existing Conditions
Traffic Volumes
Existing roadway segment (24-hour) counts with vehicle classifications were collected on Thursday,
August 6, 2015. Existing turning movement counts were collected on the same day for the AM (7:00-
9:00a.m.) and PM (4:00-6:00p.m.) peak periods at the study intersections. The City of La Quinta applies
a seasonal adjustment factor to traffic volumes collected outside of the calendar window of January 2
through March 31. Per the City’s Engineering Bulletin #06-13 (see Appendix E), traffic volumes were
increased by 20% as an adjustment for traffic counts collected during the month of August.Figure 2
shows the adjusted existing traffic volumes collected at each study intersection.
Intersection Conditions
Table 1 summarizes the intersection LOS and delay for the AM and PM peak hours under the existing
conditions. As shown in the table, all study intersections are operating at LOS C or better in both the
AM and PM peak periods.
Table 1: Existing Conditions Intersection Level of Service (2015)
Location Control
Type
AM Peak Hour PM Peak Hour
Delay
(sec)LOS Delay
(sec)LOS
1 Dune Palms Road and Blackhawk
Way/Westward Ho Drive Signalized 19.8 B 15.0 B
2 Dune Palms Road and Highway
111 Signalized 27.5 C 31.9 C
Segment Conditions
Table 2 summarizes the segment LOS. As shown in the table, the roadway segment operates at LOS A.
Table 2: Existing Conditions Segment Level of Service (2015)
Segment ADT Roadway
Designation
Number
of
Lanes
Capacity***V/C LOS
Dune Palms Road
(between Hwy 111
and Westward
Ho/Blackhawk Way)
7,508*Modified
Secondary 3**19,000 0.40 A
* Seasonally adjusted by 20%
** Existing Dune Palms Road is two lanes for southbound and one lane northbound
*** LOS F capacity of a 2-Lane divided Modified Secondary roadway from City of La Quinta General Plan, 2013
Page 7
Table 3 summarizes the current vehicle classifications for the segment of Dune Palms Road.
Table 3: Existing Conditions Vehicle Classifications (2015)
Total Roadway Segment
# of Lanes ADT
Peak Hour Total
Volume
Auto
Medium
Truck
Heavy
Truck Truck %AM PM
3* 7,508** 523 583 7,237 262 10 3.6%
* 2 lanes southbound and 1 lane northbound
Existing (Northbound)
# of Lanes ADT (NB)
Peak Hour Total
Volume
Auto
Medium
Truck
Heavy
Truck Truck %AM PM
1 3,660** 244 299 3,470 184 6 5.2%
Existing (Southbound)
# of Lanes ADT (SB)
Peak Hour Total
Volume
Auto
Medium
Truck
Heavy
Truck Truck %AM PM
2 3,767** 280 305 3,767 78 4 2.2%
** Seasonally adjusted by 20%
Pageͺ
Figure 2: Existing Traffic Volumes
Pageͻ
5.2 Future 2040 No-Build Conditions
Future Traffic Volumes
The City of La Quinta recently prepared and approved a General Plan update in 2013 that included
extensive evaluation of the future land uses and traffic volumes in the City. Regional travel forecasting
models were employed and future build-out of the City was determined to be at 2035. Build-out in the
City of La Quinta represents the maximum fulfilled land use and generated traffic volumes on the local
circulation network. Therefore, for the purposes of the future project 2040 analysis, the build-out traffic
volumes were assumed to be the same as the 2035 volumes noted the General Plan. The General Plan
includes future roadway segment volumes for Dune Palms Road as well as peak hour intersection turn
movement volumes for the two study intersections.Figure 3 shows the future traffic volumes for the
roadway segment and at each study intersection.
Intersection Conditions
Table 3 summarizes the intersection LOS and delay for the AM and PM peak hours under the future no-
build conditions. The analysis and conditions reported are according to the General Plan. As shown in
the table, all study intersections are operating at LOS D or better in both the AM and PM peak periods.
Table 3: Future 2040 No-Build Conditions Intersection Level of Service
Location Control
Type
AM Peak Hour PM Peak Hour
Delay
(sec)LOS Delay
(sec)LOS
1 Dune Palms Road and Blackhawk
Way/Westward Ho Drive Signalized 32.2 C 40.7 D
2 Dune Palms Road and Highway
111 Signalized 32.5 C 46.1 D
Segment Conditions
Table 4 summarizes the segment LOS. As shown in the table, the roadway segment operates at an
acceptable level of LOS C.
Table 4: Future 2040 No-Build Conditions Segment Level of Service
Segment ADT Roadway
Designation
Number
of
Lanes
Capacity**V/C LOS
Dune Palms Road
(between Hwy 111 and
Westward Ho Drive/
Blackhawk Way)
16,500 Modified
Secondary 3* 19,000 0.87 C
* Existing Dune Palms Road is two lanes for southbound and one lane northbound
** LOS F capacity of a 2-Lane divided Modified Secondary roadway from City of La Quinta General Plan, 2013
Page10
Figure 3: Future 2040 Traffic Volumes
Page11
5.3 Future 2040 Build Conditions
Future Traffic Volumes
The same future traffic volumes used for the future No-Build conditions are used for the Build scenario
analysis.Figure 3 shows the future traffic volumes for the roadway segment and at each study
intersection.
Intersection Conditions
Table 5 summarizes the intersection LOS and delay for the AM and PM peak hours under the future
build conditions. As shown in the table, all study intersections are operating at LOS D or better in both
the AM and PM peak periods.
Table 5: Future 2040 Build Conditions Intersection Level of Service
Location Control
Type
AM Peak Hour PM Peak Hour
Delay
(sec)LOS Delay
(sec)LOS
1 Dune Palms Road and Blackhawk
Way/Westward Ho Drive Signalized 32.2 C 40.7 D
2 Dune Palms Road and Highway
111 Signalized 32.5 C 46.1 D
Segment Conditions
Table 6 summarizes the segment LOS. As shown in the table, the roadway segment operates at an
acceptable level of LOS A.
Table 6: Future 2040 (Buildout) Build Conditions Segment Level of Service
Segment ADT Roadway
Designation
Number
of
Lanes
Capacity**V/C LOS
Dune Palms Road
(between Hwy 111 and
Westward
Ho/Blackhawk Way)
16,500 Secondary 4* 28,000 0.59 A
* Dune Palms Road proposed street section consisting of 4 lanes with median
** LOS F capacity of a 4-Lane Secondary roadway from City of La Quinta General Plan, 2013
Page12
6.Summary
This report examines traffic operations in the vicinity of the new bridge proposed for Dune Palms Road
at the CVSC.Table 7 shows the summary of roadway segment conditions for each scenario. With the
improvements to Dune Palms Road, the segment level of service improves in the future.Table 8 shows
the summary of the peak hour intersection conditions for each scenario. All of the intersections and
roadway segment operate at acceptable levels currently and in the future, with and without the project
per the General Plan. The future intersection LOS at the study intersections are not affected by the
project improvements associated with the Dune Palms Road Bridge project, rather the LOS is shown to
degrade due to the increase in traffic volumes. It is the conclusion of this report that the project and the
proposed project elements will not result in further degradation of the roadway segment or intersection
LOS for those elements analyzed herein, and that the degradation of the LOS noted for the study
intersections is due to future increases in traffic volumes. All intersections and roadway segment will
operate at acceptable levels of service in the future.
Table 7: Summary of Segment Level of Service
Segment Scenario ADT Roadway
Designation
Number
of
Lanes*
Capacity**V/C LOS
Dune Palms Road
(between Hwy 111
and Westward
Ho/Blackhawk Way)
Existing 7,508 Modified
Secondary 3 19,000 0.40 A
2040
No-Build 16,500 Modified
Secondary 3 19,000 0.87 C
2040
Build 16,500 Secondary 4 28,000 0.59 A
* Existing Dune Palms Road is two lanes for southbound and one lane northbound, future Dune Palms Road will be
4 lanes with median
** LOS F capacity of a 2-Lane divided Modified Secondary roadway (19,000), City of La Quinta General Plan, 2013
LOS F capacity of a 4-Lane Secondary roadway (28,000), City of La Quinta General Plan, 2013
Table 8: Summary of Intersection Conditions
Intersection Control
Existing (2015)No Build (2040 Buildout)Build (2040 Buildout)
AM PM AM PM AM PM
Delay LOS Delay LOS Delay LOS Delay LOS Delay LOS Delay LOS
Dune Palms
Road and
Blackhawk
Way/Westward
Ho Drive
Signal 19.8 B 15.0 B 32.2 C 40.7 D 32.2 C 40.7 D
Dune Palms
Road and
Highway 111 Signal 27.5 C 31.9 C 32.5 C 46.1 D 32.5 C 46.1 D
Appendix A
Level of Service Concept
Roadway Segment Level of Service Definitions
LOS V/C Congestion/Delay Traffic Description
(Used for surface streets, freeways, expressways and conventional highways)
"A"<0.41 None Free flow.
"B">0.41-0.62 None Free to stable flow, light to moderate
volumes.
"C">0.62-0.80 None to minimal
Stable flow, moderate volumes,
freedom to maneuver noticeably
restricted.
"D">0.80-0.92 Minimal to substantial
Approaches unstable flow, heavy
volumes, very limited freedom to
maneuver.
"E">0.92-1.00 Significant
Extremely unstable flow,
maneuverability and psychological
comfort extremely poor.
(Used for surface streets and conventional highways)
"F">1.00 Considerable
Forced or breakdown flow. Delay
measured in average travel speed
(MPH). Signalized segments
experience delays >60.0
seconds/vehicle.
(Used for freeways and expressways)
"F(0)">1.00-1.25 Considerable
0-1 hour delay
Forced flow, heavy congestion, long
queues form behind breakdown
points, stop and go.
"F(1)">1.25-1.35 Severe
1-2 hour delay
Very heavy congestion, very long
queues.
"F(2)">1.35-1.45 Very Severe
2-3 hour delay
Extremely heavy congestion, longer
queues, more numerous breakdown
points, longer stop periods.
"F(3)">1.45 Extremely Severe
3+ hours of delay Gridlock
Source: Caltrans, 1992.
Signalized Intersection Level of Service
Highway Capacity Manual Operational Analysis Method
The operational analysis method for evaluation of signalized intersections presented in the 2000
Highway Capacity Manual (Transportation Research Board Special Report 209) defines level of
service in terms of delay, or more specifically, control stopped delay per vehicle. Delay is a measure
of driver and/or passenger discomfort, frustration, fuel consumption, and lost travel time.
Control Stopped
Delay Per Vehicle
(seconds)
Level of Service (LOS) Characteristics
<10 LOS A describes operations with very low delay. This occurs when progression
is extremely favorable, and most vehicles do not stop at all. Short cycle lengths
may also contribute to low delay.
>10 – 20 LOS B describes operations with generally good progression and/or short cycle
lengths. More vehicles stop than for LOS A, causing higher levels of average
delay.
>20 – 35 LOS C describes operations with higher delays, which may result from fair
progression and/or longer cycle lengths. Individual cycle failures may begin to
appear at this level. The number of vehicles stopping is significant at this level,
although many still pass through the intersection without stopping.
>35 – 55 LOS D describes operations with high delay, resulting from some combination
of unfavorable progression, long cycle lengths, or high volumes. The influence
of congestion becomes more noticeable, and individual cycle failures are
noticeable.
>55 – 80 LOS E is considered to be the limit of acceptable delay. Individual cycle failures
are frequent occurrences.
>80 LOS F describes a condition of excessively high delay, considered unacceptable
to most drivers. This condition often occurs when arrival flow rates exceed the
capacity of the intersection. Poor progression and long cycle lengths may also
be major contributing causes to such delay.
Source: Highway Capacity Manual 2000, Exhibit 16-2
Source: City of La Quinta General Plan, 2013
Appendix B
Traffic Count Data
File Name : LQADUBLAM
Site Code : 09815420
Start Date : 8/4/2015
Page No : 1
City of La Quinta
N/S: Dune Palms Road
E/W: Blackhawk Way
Weather: Clear
Groups Printed- Total Volume
Dune Palms Road
Southbound
Westward Ho Drive
Westbound
Dune Palms Road
Northbound
Blackhawk Way
Eastbound
Start Time Left Thru Right App. Total Left Thru Right App. Total Left Thru Right App. Total Left Thru Right App. Total Int. Total
07:00 AM 2 23 2 27 2 3 2 7 1 14 3 18 1 0 2 3 55
07:15 AM 1 27 1 29 4 0 3 7 2 20 0 22 2 2 7 11 69
07:30 AM 0 29 5 34 1 7 3 11 5 21 1 27 1 4 5 10 82
07:45 AM 0 34 10 44 5 17 3 25 10 17 3 30 3 9 14 26 125
Total 3 113 18 134 12 27 11 50 18 72 7 97 7 15 28 50 331
08:00 AM 2 40 3 45 3 13 2 18 3 22 3 28 3 7 9 19 110
08:15 AM 4 36 3 43 2 10 1 13 1 23 1 25 1 5 11 17 98
08:30 AM 4 48 3 55 6 4 3 13 5 24 1 30 5 6 6 17 115
08:45 AM 0 51 6 57 6 5 3 14 1 36 1 38 0 2 2 4 113
Total 10 175 15 200 17 32 9 58 10 105 6 121 9 20 28 57 436
Grand Total 13 288 33 334 29 59 20 108 28 177 13 218 16 35 56 107 767
Apprch %3.9 86.2 9.9 26.9 54.6 18.5 12.8 81.2 6 15 32.7 52.3
Total %1.7 37.5 4.3 43.5 3.8 7.7 2.6 14.1 3.7 23.1 1.7 28.4 2.1 4.6 7.3 14
Dune Palms Road
Southbound
Westward Ho Drive
Westbound
Dune Palms Road
Northbound
Blackhawk Way
Eastbound
Start Time Left Thru Right App. Total Left Thru Right App. Total Left Thru Right App. Total Left Thru Right App. Total Int. Total
Peak Hour Analysis From 07:00 AM to 08:45 AM - Peak 1 of 1
Peak Hour for Entire Intersection Begins at 07:45 AM
07:45 AM 0 34 10 44 5 17 3 25 10 17 3 30 3 9 14 26 125
08:00 AM 2 40 3 45 3 13 2 18 3 22 3 28 3 7 9 19 110
08:15 AM 4 36 3 43 2 10 1 13 1 23 1 25 1 5 11 17 98
08:30 AM 4 48 3 55 6 4 3 13 5 24 1 30 5 6 6 17 115
Total Volume 10 158 19 187 16 44 9 69 19 86 8 113 12 27 40 79 448
% App. Total 5.3 84.5 10.2 23.2 63.8 13 16.8 76.1 7.1 15.2 34.2 50.6
PHF .625 .823 .475 .850 .667 .647 .750 .690 .475 .896 .667 .942 .600 .750 .714 .760 .896
Counts Unlimited
PO Box 1178
Corona, CA 92878
(951) 268-6268
File Name : LQADUBLAM
Site Code : 09815420
Start Date : 8/4/2015
Page No : 2
City of La Quinta
N/S: Dune Palms Road
E/W: Blackhawk Way
Weather: Clear
Dune Palms Road Blackhawk Way Westward Ho Drive Dune Palms Road
Right
19
Thru
158
Left
10
InOut Total
107 187 294 Right9 Thru44 Left16 OutTotalIn45 69 114 Left
19
Thru
86
Right
8
Out TotalIn
214 113 327 Left12 Thru27 Right40 TotalOutIn82 79 161 Peak Hour Begins at 07:45 AM
Total Volume
Peak Hour Data
North
Peak Hour Analysis From 07:00 AM to 08:45 AM - Peak 1 of 1
Peak Hour for Each Approach Begins at:
08:00 AM 07:45 AM 08:00 AM 07:45 AM
+0 mins.2 40 3 45 5 17 3 25 3 22 3 28 3 9 14 26
+15 mins.4 36 3 43 3 13 2 18 1 23 1 25 3 7 9 19
+30 mins.4 48 3 55 2 10 1 13 5 24 1 30 1 5 11 17
+45 mins.0 51 6 57 6 4 3 13 1 36 1 38 5 6 6 17
Total Volume 10 175 15 200 16 44 9 69 10 105 6 121 12 27 40 79
% App. Total 5 87.5 7.5 23.2 63.8 13 8.3 86.8 5 15.2 34.2 50.6
PHF .625 .858 .625 .877 .667 .647 .750 .690 .500 .729 .500 .796 .600 .750 .714 .760
Counts Unlimited
PO Box 1178
Corona, CA 92878
(951) 268-6268
File Name : LQADUBLPM
Site Code : 09815420
Start Date : 8/4/2015
Page No : 1
City of La Quinta
N/S: Dune Palms Road
E/W: Blackhawk Way
Weather: Clear
Groups Printed- Total Volume
Dune Palms Road
Southbound
Westward Ho Drive
Westbound
Dune Palms Road
Northbound
Blackhawk Way
Eastbound
Start Time Left Thru Right App. Total Left Thru Right App. Total Left Thru Right App. Total Left Thru Right App. Total Int. Total
04:00 PM 2 53 3 58 4 4 7 15 1 47 2 50 2 1 2 5 128
04:15 PM 0 46 5 51 1 1 3 5 3 55 6 64 3 8 6 17 137
04:30 PM 4 54 3 61 4 1 2 7 2 54 3 59 4 3 0 7 134
04:45 PM 2 55 2 59 4 4 4 12 2 57 4 63 2 2 3 7 141
Total 8 208 13 229 13 10 16 39 8 213 15 236 11 14 11 36 540
05:00 PM 1 65 1 67 3 2 3 8 2 54 8 64 2 4 3 9 148
05:15 PM 1 51 1 53 6 7 2 15 4 48 5 57 1 5 2 8 133
05:30 PM 1 49 9 59 5 3 5 13 6 62 6 74 3 3 3 9 155
05:45 PM 3 47 4 54 1 3 1 5 1 45 5 51 4 4 3 11 121
Total 6 212 15 233 15 15 11 41 13 209 24 246 10 16 11 37 557
Grand Total 14 420 28 462 28 25 27 80 21 422 39 482 21 30 22 73 1097
Apprch %3 90.9 6.1 35 31.2 33.8 4.4 87.6 8.1 28.8 41.1 30.1
Total %1.3 38.3 2.6 42.1 2.6 2.3 2.5 7.3 1.9 38.5 3.6 43.9 1.9 2.7 2 6.7
Dune Palms Road
Southbound
Westward Ho Drive
Westbound
Dune Palms Road
Northbound
Blackhawk Way
Eastbound
Start Time Left Thru Right App. Total Left Thru Right App. Total Left Thru Right App. Total Left Thru Right App. Total Int. Total
Peak Hour Analysis From 04:00 PM to 05:45 PM - Peak 1 of 1
Peak Hour for Entire Intersection Begins at 04:45 PM
04:45 PM 2 55 2 59 4 4 4 12 2 57 4 63 2 2 3 7 141
05:00 PM 1 65 1 67 3 2 3 8 2 54 8 64 2 4 3 9 148
05:15 PM 1 51 1 53 6 7 2 15 4 48 5 57 1 5 2 8 133
05:30 PM 1 49 9 59 5 3 5 13 6 62 6 74 3 3 3 9 155
Total Volume 5 220 13 238 18 16 14 48 14 221 23 258 8 14 11 33 577
% App. Total 2.1 92.4 5.5 37.5 33.3 29.2 5.4 85.7 8.9 24.2 42.4 33.3
PHF .625 .846 .361 .888 .750 .571 .700 .800 .583 .891 .719 .872 .667 .700 .917 .917 .931
Counts Unlimited
PO Box 1178
Corona, CA 92878
(951) 268-6268
File Name : LQADUBLPM
Site Code : 09815420
Start Date : 8/4/2015
Page No : 2
City of La Quinta
N/S: Dune Palms Road
E/W: Blackhawk Way
Weather: Clear
Dune Palms Road Blackhawk Way Westward Ho Drive Dune Palms Road
Right
13
Thru
220
Left
5
InOut Total
243 238 481 Right14 Thru16 Left18 OutTotalIn42 48 90 Left
14
Thru
221
Right
23
Out TotalIn
249 258 507 Left8 Thru14 Right11 TotalOutIn43 33 76 Peak Hour Begins at 04:45 PM
Total Volume
Peak Hour Data
North
Peak Hour Analysis From 04:00 PM to 05:45 PM - Peak 1 of 1
Peak Hour for Each Approach Begins at:
04:30 PM 04:45 PM 04:45 PM 04:15 PM
+0 mins.4 54 3 61 4 4 4 12 2 57 4 63 3 8 6 17
+15 mins.2 55 2 59 3 2 3 8 2 54 8 64 4 3 0 7
+30 mins.1 65 1 67 6 7 2 15 4 48 5 57 2 2 3 7
+45 mins.1 51 1 53 5 3 5 13 6 62 6 74 2 4 3 9
Total Volume 8 225 7 240 18 16 14 48 14 221 23 258 11 17 12 40
% App. Total 3.3 93.8 2.9 37.5 33.3 29.2 5.4 85.7 8.9 27.5 42.5 30
PHF .500 .865 .583 .896 .750 .571 .700 .800 .583 .891 .719 .872 .688 .531 .500 .588
Counts Unlimited
PO Box 1178
Corona, CA 92878
(951) 268-6268
Counts Unlimited, Inc.
PO Box 1178
Corona, CA 92878
951-268-6268
Location: Site Code:098-15420
N/S: Date:8/4/2015
E/W:Weather:Clear
North Leg East Leg South Leg West Leg NE to SW Leg SE to NW Leg
Dune Palms Road Blackhawk Way Dune Palms Road Westward Ho Drive --TOTAL
2 1 0 0 0 0 3
1 1 0 0 0 0 2
0 0 1 0 0 0 1
0 0 0 0 0 0 0
1 0 0 0 0 0 1
0 0 0 0 0 0 0
0 0 0 0 0 0 0
1 0 0 0 0 0 1
5 2 1 0 0 0 8
North Leg East Leg South Leg West Leg NE to SW Leg SE to NW Leg
Dune Palms Road Blackhawk Way Dune Palms Road Westward Ho Drive --TOTAL
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
1 1 0 0 0 0 2
0 0 0 0 0 0 0
1 0 0 0 0 0 1
0 0 0 0 0 0 0
2 1 0 0 0 0 3
PEDESTRIANS
7:00 AM
7:45 AM
8:00 AM
8:15 AM
7:15 AM
La Quinta
Dune Palms Road
Blackhawk Way
4:15 PM
7:30 AM
8:30 AM
8:45 AM
TOTAL VOLUMES:
4:00 PM
4:30 PM
5:30 PM
TOTAL VOLUMES:
5:45 PM
4:45 PM
5:00 PM
5:15 PM
Counts Unlimited, Inc.
PO Box 1178
Corona, CA 92878
951-268-6268
Location: Site Code:098-15420
N/S: Date:8/4/2015
E/W:Weather:Clear
North Leg East Leg South Leg West Leg NE to SW Leg SE to NW Leg
Dune Palms Road Blackhawk Way Dune Palms Road Westward Ho Drive --TOTAL
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 1 0 1
0 0 0 0 0 0 0
0 0 1 0 0 0 1
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 1 0 1 0 2
North Leg East Leg South Leg West Leg NE to SW Leg SE to NW Leg
Dune Palms Road Blackhawk Way Dune Palms Road Westward Ho Drive --TOTAL
0 0 0 1 0 0 1
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 1 0 0 1
BICYCLES
5:45 PM
TOTAL VOLUMES:
4:15 PM
4:30 PM
4:45 PM
4:00 PM
5:00 PM
5:15 PM
5:30 PM
TOTAL VOLUMES:
8:45 AM
La Quinta
Dune Palms Road
Blackhawk Way
7:00 AM
7:15 AM
7:30 AM
7:45 AM
8:00 AM
8:15 AM
8:30 AM
File Name : LQADU111AM
Site Code : 09815420
Start Date : 8/4/2015
Page No : 1
City of La Quinta
N/S: Dune Palms Road
E/W: Highway 111
Weather: Clear
Groups Printed- Total Volume
Dune Palms Road
Southbound
Highway 111
Westbound
Dune Palms Road
Northbound
Highway 111
Eastbound
Start Time Left Thru Right App. Total Left Thru Right App. Total Left Thru Right App. Total Left Thru Right App. Total Int. Total
07:00 AM 7 21 7 35 12 99 4 115 9 10 10 29 4 49 6 59 238
07:15 AM 9 21 7 37 8 117 4 129 11 9 11 31 4 90 2 96 293
07:30 AM 11 15 11 37 22 141 12 175 20 11 9 40 5 67 4 76 328
07:45 AM 16 16 15 47 10 176 14 200 21 18 23 62 3 110 5 118 427
Total 43 73 40 156 52 533 34 619 61 48 53 162 16 316 17 349 1286
08:00 AM 19 24 9 52 14 138 17 169 18 21 9 48 11 116 9 136 405
08:15 AM 14 9 11 34 18 164 9 191 14 11 7 32 6 99 2 107 364
08:30 AM 16 14 18 48 11 154 14 179 15 15 13 43 11 109 5 125 395
08:45 AM 19 24 17 60 21 159 26 206 15 19 18 52 10 130 13 153 471
Total 68 71 55 194 64 615 66 745 62 66 47 175 38 454 29 521 1635
Grand Total 111 144 95 350 116 1148 100 1364 123 114 100 337 54 770 46 870 2921
Apprch %31.7 41.1 27.1 8.5 84.2 7.3 36.5 33.8 29.7 6.2 88.5 5.3
Total %3.8 4.9 3.3 12 4 39.3 3.4 46.7 4.2 3.9 3.4 11.5 1.8 26.4 1.6 29.8
Dune Palms Road
Southbound
Highway 111
Westbound
Dune Palms Road
Northbound
Highway 111
Eastbound
Start Time Left Thru Right App. Total Left Thru Right App. Total Left Thru Right App. Total Left Thru Right App. Total Int. Total
Peak Hour Analysis From 07:00 AM to 08:45 AM - Peak 1 of 1
Peak Hour for Entire Intersection Begins at 08:00 AM
08:00 AM 19 24 9 52 14 138 17 169 18 21 9 48 11 116 9 136 405
08:15 AM 14 9 11 34 18 164 9 191 14 11 7 32 6 99 2 107 364
08:30 AM 16 14 18 48 11 154 14 179 15 15 13 43 11 109 5 125 395
08:45 AM 19 24 17 60 21 159 26 206 15 19 18 52 10 130 13 153 471
Total Volume 68 71 55 194 64 615 66 745 62 66 47 175 38 454 29 521 1635
% App. Total 35.1 36.6 28.4 8.6 82.6 8.9 35.4 37.7 26.9 7.3 87.1 5.6
PHF .895 .740 .764 .808 .762 .938 .635 .904 .861 .786 .653 .841 .864 .873 .558 .851 .868
Counts Unlimited
PO Box 1178
Corona, CA 92878
(951) 268-6268
File Name : LQADU111AM
Site Code : 09815420
Start Date : 8/4/2015
Page No : 2
City of La Quinta
N/S: Dune Palms Road
E/W: Highway 111
Weather: Clear
Dune Palms Road Highway 111 Highway 111 Dune Palms Road
Right
55
Thru
71
Left
68
InOut Total
170 194 364 Right66 Thru615 Left64 OutTotalIn569 745 1314 Left
62
Thru
66
Right
47
Out TotalIn
164 175 339 Left38 Thru454 Right29 TotalOutIn732 521 1253 Peak Hour Begins at 08:00 AM
Total Volume
Peak Hour Data
North
Peak Hour Analysis From 07:00 AM to 08:45 AM - Peak 1 of 1
Peak Hour for Each Approach Begins at:
08:00 AM 08:00 AM 07:45 AM 08:00 AM
+0 mins.19 24 9 52 14 138 17 169 21 18 23 62 11 116 9 136
+15 mins.14 9 11 34 18 164 9 191 18 21 9 48 6 99 2 107
+30 mins.16 14 18 48 11 154 14 179 14 11 7 32 11 109 5 125
+45 mins.19 24 17 60 21 159 26 206 15 15 13 43 10 130 13 153
Total Volume 68 71 55 194 64 615 66 745 68 65 52 185 38 454 29 521
% App. Total 35.1 36.6 28.4 8.6 82.6 8.9 36.8 35.1 28.1 7.3 87.1 5.6
PHF .895 .740 .764 .808 .762 .938 .635 .904 .810 .774 .565 .746 .864 .873 .558 .851
Counts Unlimited
PO Box 1178
Corona, CA 92878
(951) 268-6268
File Name : LQADU111PM
Site Code : 09815420
Start Date : 8/4/2015
Page No : 1
City of La Quinta
N/S: Dune Palms Road
E/W: Highway 111
Weather: Clear
Groups Printed- Total Volume
Dune Palms Road
Southbound
Highway 111
Westbound
Dune Palms Road
Northbound
Highway 111
Eastbound
Start Time Left Thru Right App. Total Left Thru Right App. Total Left Thru Right App. Total Left Thru Right App. Total Int. Total
04:00 PM 18 25 22 65 25 177 23 225 15 17 17 49 19 258 20 297 636
04:15 PM 39 25 12 76 35 207 13 255 14 17 19 50 26 288 32 346 727
04:30 PM 24 28 17 69 22 180 23 225 25 21 20 66 26 250 19 295 655
04:45 PM 22 29 24 75 25 212 27 264 21 18 22 61 18 243 23 284 684
Total 103 107 75 285 107 776 86 969 75 73 78 226 89 1039 94 1222 2702
05:00 PM 43 39 15 97 20 184 23 227 18 11 28 57 30 225 19 274 655
05:15 PM 30 31 13 74 25 201 21 247 20 14 14 48 27 290 28 345 714
05:30 PM 20 27 9 56 33 165 29 227 12 18 25 55 20 264 27 311 649
05:45 PM 27 17 14 58 23 180 18 221 20 19 28 67 14 219 19 252 598
Total 120 114 51 285 101 730 91 922 70 62 95 227 91 998 93 1182 2616
Grand Total 223 221 126 570 208 1506 177 1891 145 135 173 453 180 2037 187 2404 5318
Apprch %39.1 38.8 22.1 11 79.6 9.4 32 29.8 38.2 7.5 84.7 7.8
Total %4.2 4.2 2.4 10.7 3.9 28.3 3.3 35.6 2.7 2.5 3.3 8.5 3.4 38.3 3.5 45.2
Dune Palms Road
Southbound
Highway 111
Westbound
Dune Palms Road
Northbound
Highway 111
Eastbound
Start Time Left Thru Right App. Total Left Thru Right App. Total Left Thru Right App. Total Left Thru Right App. Total Int. Total
Peak Hour Analysis From 04:00 PM to 05:45 PM - Peak 1 of 1
Peak Hour for Entire Intersection Begins at 04:15 PM
04:15 PM 39 25 12 76 35 207 13 255 14 17 19 50 26 288 32 346 727
04:30 PM 24 28 17 69 22 180 23 225 25 21 20 66 26 250 19 295 655
04:45 PM 22 29 24 75 25 212 27 264 21 18 22 61 18 243 23 284 684
05:00 PM 43 39 15 97 20 184 23 227 18 11 28 57 30 225 19 274 655
Total Volume 128 121 68 317 102 783 86 971 78 67 89 234 100 1006 93 1199 2721
% App. Total 40.4 38.2 21.5 10.5 80.6 8.9 33.3 28.6 38 8.3 83.9 7.8
PHF .744 .776 .708 .817 .729 .923 .796 .920 .780 .798 .795 .886 .833 .873 .727 .866 .936
Counts Unlimited
PO Box 1178
Corona, CA 92878
(951) 268-6268
File Name : LQADU111PM
Site Code : 09815420
Start Date : 8/4/2015
Page No : 2
City of La Quinta
N/S: Dune Palms Road
E/W: Highway 111
Weather: Clear
Dune Palms Road Highway 111 Highway 111 Dune Palms Road
Right
68
Thru
121
Left
128
InOut Total
253 317 570 Right86 Thru783 Left102 OutTotalIn1223 971 2194 Left
78
Thru
67
Right
89
Out TotalIn
316 234 550 Left100 Thru1006 Right93 TotalOutIn929 1199 2128 Peak Hour Begins at 04:15 PM
Total Volume
Peak Hour Data
North
Peak Hour Analysis From 04:00 PM to 05:45 PM - Peak 1 of 1
Peak Hour for Each Approach Begins at:
04:15 PM 04:15 PM 04:15 PM 04:00 PM
+0 mins.39 25 12 76 35 207 13 255 14 17 19 50 19 258 20 297
+15 mins.24 28 17 69 22 180 23 225 25 21 20 66 26 288 32 346
+30 mins.22 29 24 75 25 212 27 264 21 18 22 61 26 250 19 295
+45 mins.43 39 15 97 20 184 23 227 18 11 28 57 18 243 23 284
Total Volume 128 121 68 317 102 783 86 971 78 67 89 234 89 1039 94 1222
% App. Total 40.4 38.2 21.5 10.5 80.6 8.9 33.3 28.6 38 7.3 85 7.7
PHF .744 .776 .708 .817 .729 .923 .796 .920 .780 .798 .795 .886 .856 .902 .734 .883
Counts Unlimited
PO Box 1178
Corona, CA 92878
(951) 268-6268
Counts Unlimited, Inc.
PO Box 1178
Corona, CA 92878
951-268-6268
Location: Site Code:098-15420
N/S: Date:8/4/2015
E/W:Weather:Clear
North Leg East Leg South Leg West Leg
Dune Palms Road Highway 111 Dune Palms Road Highway 111 TOTAL
0 2 0 2 4
0 0 0 2 2
1 0 1 0 2
0 0 0 2 2
0 0 0 0 0
0 0 0 0 0
0 0 0 2 2
0 0 0 0 0
1 2 1 8 12
North Leg East Leg South Leg West Leg
Dune Palms Road Highway 111 Dune Palms Road Highway 111 TOTAL
1 0 1 1 3
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 1 1
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
1 0 1 2 4
4:30 PM
5:30 PM
TOTAL VOLUMES:
5:45 PM
4:45 PM
5:00 PM
5:15 PM
La Quinta
Dune Palms Road
Highway 111
4:15 PM
7:30 AM
8:30 AM
8:45 AM
TOTAL VOLUMES:
4:00 PM
PEDESTRIANS
7:00 AM
7:45 AM
8:00 AM
8:15 AM
7:15 AM
Counts Unlimited, Inc.
PO Box 1178
Corona, CA 92878
951-268-6268
Location: Site Code:098-15420
N/S: Date:8/4/2015
E/W:Weather:Clear
North Leg East Leg South Leg West Leg
Dune Palms Road Highway 111 Dune Palms Road Highway 111 TOTAL
0 0 0 0 0
0 0 0 0 0
0 1 1 1 3
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 1 3 1 5
0 0 0 0 0
0 2 4 2 8
North Leg East Leg South Leg West Leg
Dune Palms Road Highway 111 Dune Palms Road Highway 111 TOTAL
2 0 0 0 2
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 1 1
0 1 1 0 2
1 0 0 1 2
0 0 0 0 0
3 1 1 2 7
5:15 PM
5:30 PM
BICYCLES
8:45 AM
La Quinta
Dune Palms Road
Highway 111
7:00 AM
7:15 AM
7:30 AM
7:45 AM
8:00 AM
8:15 AM
8:30 AM
TOTAL VOLUMES:
4:15 PM
4:30 PM
4:45 PM
4:00 PM
5:00 PM
5:45 PM
TOTAL VOLUMES:
Page 1
City of La Quinta
Dune Palms Road
S/ Blackhawk Way
24 Hour Directional Classification Count
LQADBSBH
Site Code: 098-15420
Counts Unlimited, Inc
PO Box 1178
Corona, CA 92878
Phone: 951-268-6268
email: counts@countsunlimited.com
Northbound
Start Cars &2 Axle 2 Axle 3 Axle 4 Axle <5 Axl 5 Axle >6 Axl <6 Axl 6 Axle >6 Axl
Time Bikes Trailers Long Buses 6 Tire Single Single Double Double Double Multi Multi Multi Total
08/06/15 0 16 4 0 1 0 0 0 0 0 0 0 0 21
01:00 0 8 0 0 0 0 0 0 0 0 0 0 0 8
02:00 0 8 0 0 0 0 0 0 0 0 0 0 0 8
03:00 0 1 1 0 0 0 0 0 0 0 0 0 0 2
04:00 0 9 3 0 1 0 0 0 0 0 0 0 0 13
05:00 0 26 11 0 3 0 0 0 0 0 0 0 0 40
06:00 0 53 24 0 5 0 0 1 0 0 0 0 0 83
07:00 1 73 21 1 8 0 0 0 0 0 0 0 0 104
08:00 0 82 32 0 1 0 0 0 0 0 0 0 0 115
09:00 0 110 30 0 8 0 0 0 0 0 0 0 0 148
10:00 0 130 31 1 11 0 0 0 0 0 0 0 0 173
11:00 0 147 43 0 12 0 0 1 0 0 0 0 0 203
12 PM 0 170 58 0 17 0 0 0 0 0 0 0 0 245
13:00 0 159 35 0 11 0 0 1 0 0 0 0 0 206
14:00 1 163 40 1 8 1 0 1 0 0 0 0 0 215
15:00 0 169 40 0 14 0 0 0 0 0 0 0 0 223
16:00 0 180 47 0 9 1 0 0 0 0 0 0 0 237
17:00 1 198 43 0 8 0 0 0 0 0 0 0 0 250
18:00 0 164 35 0 8 0 0 0 0 0 0 0 0 207
19:00 0 143 33 1 8 0 0 0 0 0 0 0 0 185
20:00 0 123 29 1 5 0 0 1 0 0 0 0 0 159
21:00 0 79 30 0 5 0 0 0 0 0 0 0 0 114
22:00 0 57 8 0 2 0 0 0 0 0 0 0 0 67
23:00 0 20 6 0 1 0 0 0 0 0 0 0 0 27
Total 3 2288 604 5 146 2 0 5 0 0 0 0 0 3053
Percent 0.1%74.9%19.8%0.2%4.8%0.1%0.0%0.2%0.0%0.0%0.0%0.0%0.0%
AM Peak 07:00 11:00 11:00 07:00 11:00 06:00 11:00
Vol.1 147 43 1 12 1 203
PM Peak 14:00 17:00 12:00 14:00 12:00 14:00 13:00 17:00
Vol.1 198 58 1 17 1 1 250
Grand
Total 3 2288 604 5 146 2 0 5 0 0 0 0 0 3053
Percent 0.1%74.9%19.8%0.2%4.8%0.1%0.0%0.2%0.0%0.0%0.0%0.0%0.0%
Page 2
City of La Quinta
Dune Palms Road
S/ Blackhawk Way
24 Hour Directional Classification Count
LQADBSBH
Site Code: 098-15420
Counts Unlimited, Inc
PO Box 1178
Corona, CA 92878
Phone: 951-268-6268
email: counts@countsunlimited.com
Southbound
Start Cars &2 Axle 2 Axle 3 Axle 4 Axle <5 Axl 5 Axle >6 Axl <6 Axl 6 Axle >6 Axl
Time Bikes Trailers Long Buses 6 Tire Single Single Double Double Double Multi Multi Multi Total
08/06/15 0 20 3 0 0 0 0 0 0 0 0 0 0 23
01:00 0 3 1 0 0 0 0 0 0 0 0 0 0 4
02:00 0 3 1 0 0 0 0 0 0 0 0 0 0 4
03:00 0 3 1 0 1 0 0 0 0 0 0 0 0 5
04:00 0 11 8 0 1 0 0 0 0 0 0 0 0 20
05:00 0 33 4 0 1 0 0 0 0 0 0 0 0 38
06:00 0 67 18 0 2 0 0 0 0 0 0 0 0 87
07:00 0 117 22 0 4 0 0 0 0 0 0 0 0 143
08:00 1 176 36 0 2 1 0 1 0 0 0 0 0 217
09:00 1 176 33 0 9 0 0 0 0 0 0 0 0 219
10:00 0 188 32 0 4 0 0 0 0 0 0 0 0 224
11:00 0 186 40 0 7 0 0 0 0 0 0 0 0 233
12 PM 0 169 39 0 5 1 0 1 0 0 0 0 0 215
13:00 0 177 31 0 7 0 0 0 0 0 0 0 0 215
14:00 1 172 28 0 3 0 0 1 0 0 0 0 0 205
15:00 0 210 40 0 3 1 0 0 0 0 0 0 0 254
16:00 0 182 46 0 3 1 0 0 0 0 0 0 0 232
17:00 1 198 33 0 6 0 0 0 0 0 0 0 0 238
18:00 0 188 35 0 1 0 0 0 0 0 0 0 0 224
19:00 0 123 20 0 2 0 0 0 0 0 0 0 0 145
20:00 2 102 17 0 0 0 0 0 0 0 0 0 0 121
21:00 0 67 6 0 0 0 0 0 0 0 0 0 0 73
22:00 0 34 9 0 0 0 0 0 0 0 0 0 0 43
23:00 0 29 2 0 0 0 0 0 0 0 0 0 0 31
Total 6 2634 505 0 61 4 0 3 0 0 0 0 0 3213
Percent 0.2%82.0%15.7%0.0%1.9%0.1%0.0%0.1%0.0%0.0%0.0%0.0%0.0%
AM Peak 08:00 10:00 11:00 09:00 08:00 08:00 11:00
Vol.1 188 40 9 1 1 233
PM Peak 20:00 15:00 16:00 13:00 12:00 12:00 15:00
Vol.2 210 46 7 1 1 254
Grand
Total 6 2634 505 0 61 4 0 3 0 0 0 0 0 3213
Percent 0.2%82.0%15.7%0.0%1.9%0.1%0.0%0.1%0.0%0.0%0.0%0.0%0.0%
Page 3
City of La Quinta
Dune Palms Road
S/ Blackhawk Way
24 Hour Directional Classification Count
LQADBSBH
Site Code: 098-15420
Counts Unlimited, Inc
PO Box 1178
Corona, CA 92878
Phone: 951-268-6268
email: counts@countsunlimited.com
Northbound, Southbound
Start Cars &2 Axle 2 Axle 3 Axle 4 Axle <5 Axl 5 Axle >6 Axl <6 Axl 6 Axle >6 Axl
Time Bikes Trailers Long Buses 6 Tire Single Single Double Double Double Multi Multi Multi Total
08/06/15 0 36 7 0 1 0 0 0 0 0 0 0 0 44
01:00 0 11 1 0 0 0 0 0 0 0 0 0 0 12
02:00 0 11 1 0 0 0 0 0 0 0 0 0 0 12
03:00 0 4 2 0 1 0 0 0 0 0 0 0 0 7
04:00 0 20 11 0 2 0 0 0 0 0 0 0 0 33
05:00 0 59 15 0 4 0 0 0 0 0 0 0 0 78
06:00 0 120 42 0 7 0 0 1 0 0 0 0 0 170
07:00 1 190 43 1 12 0 0 0 0 0 0 0 0 247
08:00 1 258 68 0 3 1 0 1 0 0 0 0 0 332
09:00 1 286 63 0 17 0 0 0 0 0 0 0 0 367
10:00 0 318 63 1 15 0 0 0 0 0 0 0 0 397
11:00 0 333 83 0 19 0 0 1 0 0 0 0 0 436
12 PM 0 339 97 0 22 1 0 1 0 0 0 0 0 460
13:00 0 336 66 0 18 0 0 1 0 0 0 0 0 421
14:00 2 335 68 1 11 1 0 2 0 0 0 0 0 420
15:00 0 379 80 0 17 1 0 0 0 0 0 0 0 477
16:00 0 362 93 0 12 2 0 0 0 0 0 0 0 469
17:00 2 396 76 0 14 0 0 0 0 0 0 0 0 488
18:00 0 352 70 0 9 0 0 0 0 0 0 0 0 431
19:00 0 266 53 1 10 0 0 0 0 0 0 0 0 330
20:00 2 225 46 1 5 0 0 1 0 0 0 0 0 280
21:00 0 146 36 0 5 0 0 0 0 0 0 0 0 187
22:00 0 91 17 0 2 0 0 0 0 0 0 0 0 110
23:00 0 49 8 0 1 0 0 0 0 0 0 0 0 58
Total 9 4922 1109 5 207 6 0 8 0 0 0 0 0 6266
Percent 0.1%78.6%17.7%0.1%3.3%0.1%0.0%0.1%0.0%0.0%0.0%0.0%0.0%
AM Peak 07:00 11:00 11:00 07:00 11:00 08:00 06:00 11:00
Vol.1 333 83 1 19 1 1 436
PM Peak 14:00 17:00 12:00 14:00 12:00 16:00 14:00 17:00
Vol.2 396 97 1 22 2 2 488
Grand
Total 9 4922 1109 5 207 6 0 8 0 0 0 0 0 6266
Percent 0.1%78.6%17.7%0.1%3.3%0.1%0.0%0.1%0.0%0.0%0.0%0.0%0.0%
Appendix C
Existing Conditions
Peak Hour Intersection Analysis Worksheets
Existing Conditions AM
1: Dune Palms Road & Blackhawk Way 8/18/2015
Parsons Brinckerhoff Page 1
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Volume (vph) 14 32 48 19 53 11 23 103 10 12 190 23
Ideal Flow (vphpl) 1900 1900 1900 1900 1900 1900 1900 1900 1900 1900 1900 1900
Total Lost time (s) 5.0 6.5 5.0 6.5 5.0 5.0 7.0 7.0 5.0 7.0 5.0
Lane Util. Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
Frt 1.00 0.91 1.00 1.00 0.85 1.00 1.00 0.85 1.00 1.00 0.85
Flt Protected 0.95 1.00 0.95 1.00 1.00 0.95 1.00 1.00 0.95 1.00 1.00
Satd. Flow (prot) 1770 1695 1770 1863 1583 1770 1863 1583 1770 1863 1583
Flt Permitted 0.95 1.00 0.95 1.00 1.00 0.95 1.00 1.00 0.95 1.00 1.00
Satd. Flow (perm) 1770 1695 1770 1863 1583 1770 1863 1583 1770 1863 1583
Peak-hour factor, PHF 0.76 0.76 0.76 0.69 0.69 0.69 0.94 0.94 0.94 0.85 0.85 0.65
Adj. Flow (vph) 18 42 63 28 77 16 24 110 11 14 224 35
RTOR Reduction (vph) 0 45 0 0 0 14 0070019
Lane Group Flow (vph) 18 60 0 28 77 2 24 110 4 14 224 16
Turn Type Prot NA Prot NA pm+ov Prot NA Perm Prot NA pm+ov
Protected Phases 5 2 16374 385
Permitted Phases 6 4 8
Actuated Green, G (s) 4.4 9.2 1.3 6.1 8.8 1.3 21.3 21.3 2.7 22.7 27.1
Effective Green, g (s) 4.4 9.2 1.3 6.1 8.8 1.3 21.3 21.3 2.7 22.7 27.1
Actuated g/C Ratio 0.08 0.16 0.02 0.11 0.15 0.02 0.37 0.37 0.05 0.39 0.47
Clearance Time (s) 5.0 6.5 5.0 6.5 5.0 5.0 7.0 7.0 5.0 7.0 5.0
Vehicle Extension (s) 1.5 4.0 1.5 4.0 1.5 1.5 4.0 4.0 1.5 4.0 1.5
Lane Grp Cap (vph) 134 268 39 195 240 39 684 581 82 729 739
v/s Ratio Prot 0.01 c0.04 c0.02 c0.04 0.00 c0.01 0.06 0.01 c0.12 0.00
v/s Ratio Perm 0.00 0.00 0.01
v/c Ratio 0.13 0.23 0.72 0.39 0.01 0.62 0.16 0.01 0.17 0.31 0.02
Uniform Delay, d1 25.0 21.3 28.2 24.2 20.9 28.1 12.3 11.6 26.6 12.2 8.3
Progression Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
Incremental Delay, d2 0.2 0.6 40.9 1.8 0.0 18.5 0.2 0.0 0.4 0.3 0.0
Delay (s) 25.2 21.9 69.0 26.0 20.9 46.6 12.5 11.6 26.9 12.5 8.3
Level of Service C C E C C D B B C B A
Approach Delay (s) 22.4 35.3 18.1 12.7
Approach LOS C D B B
Intersection Summary
HCM 2000 Control Delay 19.8 HCM 2000 Level of Service B
HCM 2000 Volume to Capacity ratio 0.37
Actuated Cycle Length (s) 58.0 Sum of lost time (s) 27.5
Intersection Capacity Utilization 38.1% ICU Level of Service A
Analysis Period (min) 15
c Critical Lane Group
Existing Conditions AM
2: Dune Palms Road & Highway 111 8/18/2015
Parsons Brinckerhoff Page 2
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Volume (vph) 46 545 35 77 738 79 74 79 56 82 85 66
Ideal Flow (vphpl) 1900 1900 1900 1900 1900 1900 1900 1900 1900 1900 1900 1900
Total Lost time (s) 5.0 7.0 7.0 5.0 7.0 7.0 5.0 7.0 7.0 5.0 7.0 7.0
Lane Util. Factor 0.97 0.95 1.00 0.97 0.95 1.00 0.97 0.95 1.00 0.97 0.95 1.00
Frpb, ped/bikes 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.99
Flpb, ped/bikes 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
Frt 1.00 1.00 0.85 1.00 1.00 0.85 1.00 1.00 0.85 1.00 1.00 0.85
Flt Protected 0.95 1.00 1.00 0.95 1.00 1.00 0.95 1.00 1.00 0.95 1.00 1.00
Satd. Flow (prot) 3433 3539 1583 3433 3539 1583 3433 3539 1583 3433 3539 1561
Flt Permitted 0.95 1.00 1.00 0.95 1.00 1.00 0.95 1.00 1.00 0.95 1.00 1.00
Satd. Flow (perm) 3433 3539 1583 3433 3539 1583 3433 3539 1583 3433 3539 1561
Peak-hour factor, PHF 0.85 0.85 0.85 0.90 0.90 0.90 0.84 0.84 0.84 0.81 0.81 0.81
Adj. Flow (vph) 54 641 41 86 820 88 88 94 67 101 105 81
RTOR Reduction (vph) 0 0 20 0 0 42 0 0 60 0 0 71
Lane Group Flow (vph) 54 641 21 86 820 46 88 94 7 101 105 10
Confl. Peds. (#/hr) 2 2
Turn Type Prot NA Perm Prot NA Perm Prot NA Perm Prot NA Perm
Protected Phases 5 2 1 6 7 4 3 8
Permitted Phases 2648
Actuated Green, G (s) 9.6 60.7 60.7 12.3 63.4 63.4 8.8 12.0 12.0 11.0 14.2 14.2
Effective Green, g (s) 9.6 60.7 60.7 12.3 63.4 63.4 8.8 12.0 12.0 11.0 14.2 14.2
Actuated g/C Ratio 0.08 0.51 0.51 0.10 0.53 0.53 0.07 0.10 0.10 0.09 0.12 0.12
Clearance Time (s) 5.0 7.0 7.0 5.0 7.0 7.0 5.0 7.0 7.0 5.0 7.0 7.0
Vehicle Extension (s) 1.5 2.0 2.0 1.5 2.0 2.0 1.5 2.0 2.0 1.5 2.0 2.0
Lane Grp Cap (vph) 274 1790 800 351 1869 836 251 353 158 314 418 184
v/s Ratio Prot 0.02 c0.18 0.03 c0.23 c0.03 c0.03 c0.03 0.03
v/s Ratio Perm 0.01 0.03 0.00 0.01
v/c Ratio 0.20 0.36 0.03 0.25 0.44 0.06 0.35 0.27 0.04 0.32 0.25 0.05
Uniform Delay, d1 51.6 17.9 14.8 49.6 17.4 13.8 52.9 49.9 48.8 51.0 48.1 46.9
Progression Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
Incremental Delay, d2 0.1 0.6 0.1 0.1 0.8 0.1 0.3 0.1 0.0 0.2 0.1 0.0
Delay (s) 51.7 18.5 14.9 49.7 18.1 13.9 53.2 50.1 48.8 51.2 48.2 47.0
Level of Service D B B D B B DDDDDD
Approach Delay (s) 20.7 20.5 50.8 48.9
Approach LOS CCDD
Intersection Summary
HCM 2000 Control Delay 27.5 HCM 2000 Level of Service C
HCM 2000 Volume to Capacity ratio 0.41
Actuated Cycle Length (s) 120.0 Sum of lost time (s) 24.0
Intersection Capacity Utilization 55.6% ICU Level of Service B
Analysis Period (min) 15
c Critical Lane Group
Existing Conditions PM
1: Dune Palms Road & Blackhawk Way 8/18/2015
Parsons Brinckerhoff Page 1
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Volume (vph) 10 17 13 22 19 17 17 265 28 6 264 16
Ideal Flow (vphpl) 1900 1900 1900 1900 1900 1900 1900 1900 1900 1900 1900 1900
Total Lost time (s) 5.0 6.5 5.0 6.5 5.0 5.0 7.0 7.0 5.0 7.0 5.0
Lane Util. Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
Frt 1.00 0.93 1.00 1.00 0.85 1.00 1.00 0.85 1.00 1.00 0.85
Flt Protected 0.95 1.00 0.95 1.00 1.00 0.95 1.00 1.00 0.95 1.00 1.00
Satd. Flow (prot) 1770 1741 1770 1863 1583 1770 1863 1583 1770 1863 1583
Flt Permitted 0.95 1.00 0.95 1.00 1.00 0.95 1.00 1.00 0.95 1.00 1.00
Satd. Flow (perm) 1770 1741 1770 1863 1583 1770 1863 1583 1770 1863 1583
Peak-hour factor, PHF 0.76 0.76 0.76 0.69 0.69 0.69 0.94 0.94 0.94 0.85 0.85 0.85
Adj. Flow (vph) 13 22 17 32 28 25 18 282 30 7 311 19
RTOR Reduction (vph) 0 16 0 0 0 23 0 0 17 0 0 9
Lane Group Flow (vph) 13 23 0 32 28 2 18 282 13 7 311 10
Turn Type Prot NA Prot NA pm+ov Prot NA Perm Prot NA pm+ov
Protected Phases 5 2 16374 385
Permitted Phases 6 4 8
Actuated Green, G (s) 4.7 3.5 2.5 1.3 3.8 1.3 25.3 25.3 2.5 26.5 31.2
Effective Green, g (s) 4.7 3.5 2.5 1.3 3.8 1.3 25.3 25.3 2.5 26.5 31.2
Actuated g/C Ratio 0.08 0.06 0.04 0.02 0.07 0.02 0.44 0.44 0.04 0.46 0.54
Clearance Time (s) 5.0 6.5 5.0 6.5 5.0 5.0 7.0 7.0 5.0 7.0 5.0
Vehicle Extension (s) 1.5 4.0 1.5 4.0 1.5 1.5 4.0 4.0 1.5 4.0 1.5
Lane Grp Cap (vph) 145 106 77 42 104 40 822 698 77 861 861
v/s Ratio Prot 0.01 0.01 c0.02 c0.02 0.00 c0.01 0.15 0.00 c0.17 0.00
v/s Ratio Perm 0.00 0.01 0.01
v/c Ratio 0.09 0.22 0.42 0.67 0.02 0.45 0.34 0.02 0.09 0.36 0.01
Uniform Delay, d1 24.3 25.6 26.7 27.8 25.0 27.6 10.5 9.0 26.3 9.9 6.0
Progression Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
Incremental Delay, d2 0.1 1.4 1.3 36.2 0.0 2.9 0.3 0.0 0.2 0.4 0.0
Delay (s) 24.4 27.0 28.0 64.0 25.0 30.6 10.9 9.0 26.5 10.3 6.0
Level of Service C C C E C C B A C B A
Approach Delay (s) 26.4 39.0 11.8 10.4
Approach LOS C D B B
Intersection Summary
HCM 2000 Control Delay 15.0 HCM 2000 Level of Service B
HCM 2000 Volume to Capacity ratio 0.40
Actuated Cycle Length (s) 57.3 Sum of lost time (s) 27.5
Intersection Capacity Utilization 43.1% ICU Level of Service A
Analysis Period (min) 15
c Critical Lane Group
Existing Conditions PM
2: Dune Palms Road & Highway 111 8/18/2015
Parsons Brinckerhoff Page 2
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Volume (vph) 120 1207 112 122 940 103 94 80 107 154 145 82
Ideal Flow (vphpl) 1900 1900 1900 1900 1900 1900 1900 1900 1900 1900 1900 1900
Total Lost time (s) 5.0 7.0 7.0 5.0 7.0 7.0 5.0 7.0 7.0 5.0 7.0 7.0
Lane Util. Factor 0.97 0.95 1.00 0.97 0.95 1.00 0.97 0.95 1.00 0.97 0.95 1.00
Frt 1.00 1.00 0.85 1.00 1.00 0.85 1.00 1.00 0.85 1.00 1.00 0.85
Flt Protected 0.95 1.00 1.00 0.95 1.00 1.00 0.95 1.00 1.00 0.95 1.00 1.00
Satd. Flow (prot) 3433 3539 1583 3433 3539 1583 3433 3539 1583 3433 3539 1583
Flt Permitted 0.95 1.00 1.00 0.95 1.00 1.00 0.95 1.00 1.00 0.95 1.00 1.00
Satd. Flow (perm) 3433 3539 1583 3433 3539 1583 3433 3539 1583 3433 3539 1583
Peak-hour factor, PHF 0.87 0.87 0.87 0.92 0.92 0.92 0.89 0.89 0.89 0.82 0.82 0.82
Adj. Flow (vph) 138 1387 129 133 1022 112 106 90 120 188 177 100
RTOR Reduction (vph) 0 0 59 0 0 51 0 0 110 0 0 91
Lane Group Flow (vph) 138 1387 70 133 1022 61 106 90 10 188 177 9
Turn Type Prot NA Perm Prot NA Perm Prot NA Perm Prot NA Perm
Protected Phases 5 2 1 6 7 4 3 8
Permitted Phases 2648
Actuated Green, G (s) 12.0 70.1 70.1 13.0 71.1 71.1 11.0 11.2 11.2 11.7 11.9 11.9
Effective Green, g (s) 12.0 70.1 70.1 13.0 71.1 71.1 11.0 11.2 11.2 11.7 11.9 11.9
Actuated g/C Ratio 0.09 0.54 0.54 0.10 0.55 0.55 0.08 0.09 0.09 0.09 0.09 0.09
Clearance Time (s) 5.0 7.0 7.0 5.0 7.0 7.0 5.0 7.0 7.0 5.0 7.0 7.0
Vehicle Extension (s) 1.5 2.0 2.0 1.5 2.0 2.0 1.5 2.0 2.0 1.5 2.0 2.0
Lane Grp Cap (vph) 316 1908 853 343 1935 865 290 304 136 308 323 144
v/s Ratio Prot 0.04 c0.39 0.04 c0.29 c0.03 0.03 c0.05 0.05
v/s Ratio Perm 0.04 0.04 0.01 0.01
v/c Ratio 0.44 0.73 0.08 0.39 0.53 0.07 0.37 0.30 0.08 0.61 0.55 0.06
Uniform Delay, d1 55.8 22.7 14.4 54.8 18.8 13.9 56.2 55.7 54.6 57.0 56.5 54.0
Progression Factor 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
Incremental Delay, d2 0.4 2.5 0.2 0.3 1.0 0.2 0.3 0.2 0.1 2.5 1.0 0.1
Delay (s) 56.2 25.2 14.6 55.0 19.8 14.0 56.5 55.9 54.7 59.5 57.5 54.0
Level of Service E C BEBBEEDEED
Approach Delay (s) 26.9 23.0 55.7 57.5
Approach LOS C C E E
Intersection Summary
HCM 2000 Control Delay 31.9 HCM 2000 Level of Service C
HCM 2000 Volume to Capacity ratio 0.65
Actuated Cycle Length (s) 130.0 Sum of lost time (s) 24.0
Intersection Capacity Utilization 81.7% ICU Level of Service D
Analysis Period (min) 15
c Critical Lane Group
Appendix D
Future 2040 No-Build/Build Conditions
Peak Hour Intersection Analysis Worksheets
The following are excerpts from the City of La Quinta General Plan Circulation
Element Update Traffic Impact Analysis, May 14, 2012.
Appendix E
City of La Quinta Engineering Bulletin #06-13