2024 Engineering & Traffic Survey - Dune Palms Rd (Oct 1)WWI LLDAN
Engineering
October 16, 2024
County of Riverside Superior Courts
Larson Justice Center
46-200 Oasis Street
Indio, CA 92201
SUBJECT: 2024 Engineering and Traffic Survey
City of La Quinta
Dear Larson Justice Center / County of Riverside Superior Courts,
extending
your
reach
California Vehicle Code Sections 40801 and 40802 require Engineering and Traffic Surveys (ETS) to
establish or revise prima facie speed limits on certain streets within a local jurisdiction before law
enforcement can utilize radar or other electronic speed measuring devices for speed enforcement. These
surveys must be updated every five, seven, or ten years to ensure the speeds reflect current conditions as
dictated by the California Vehicle Code. The surveys can be extended from 5 to 7 years provided the
City's police officer(s) have completed a 24-hour radar operator course [CVC 40802(c)(2)(B)(i)(I)].
Additionally, some surveys may be extended to fourteen years if the City Traffic Engineer certifies there
have been no significant changes to the roadway segment(s) or traffic conditions [CVC
40802(c)(2)(B)(i)(II)]. These provisions ensure that posted speed limits are kept reasonably current.
This letter is to certify that I am the licensed and duly designated Traffic Engineer for the City of La
Quinta. I have evaluated six street segments that are part of the 2024 ETS. Attached is the resolution
adopting new speed limits and a copy of the E&T Study. Therefore, based on the above reasons, the
most recent Engineering and Traffic Survey shall be effective 30 days after the adopted date of the
particular ETS conducted for the following street segment:
• Dune Palms Drive from Mile Avenue to Fred waring Drive — 35 mph
If you have any questions, you may contact Mr. Bryan McKinney, Public Works Director at (760) 777-
7045 or myself, at (562) 364-8526.
Sincerely,
Nicolle Spann, P.E., T.E.
Traffic Engineer
Cc: City Attorney
City Clerk
Riverside County Sheriff s Department
*FESS/
S.
CC
*
z
TR 2933
RAFF�1. G
OF cA.
Engineering 1 Geotechnical 1 Environmental 1 Sustainability 1 Financial 1 Homeland Security
562.908.6200 1 800.499.4484 1 fax: 562.695.2120 1 13191 Crossroads Parkway North, Suite 405, Industry, CA 91746-3443 1 www.willdan.com
�WI LLDAN I your extending
Engineering reach
October 16, 2024
County of Riverside Superior Courts
Larson Justice Center
46-200 Oasis Street
Indio, CA 92201
SUBJECT: 2024 Engineering and Traffic Survey
City of La Quinta
Dear Larson Justice Center / County of Riverside Superior Courts,
California Vehicle Code Sections 40801 and 40802 require Engineering and Traffic Surveys (ETS) to
establish or revise prima facie speed limits on certain streets within a local jurisdiction before law
enforcement can utilize radar or other electronic speed measuring devices for speed enforcement. These
surveys must be updated every five, seven, or ten years to ensure the speeds reflect current conditions as
dictated by the California Vehicle Code. The surveys can be extended from 5 to 7 years provided the
City's police officer(s) have completed a 24-hour radar operator course [CVC 40802(c)(2)(B)(i)(I)].
Additionally, some surveys may be extended to fourteen years if the City Traffic Engineer certifies there
have been no significant changes to the roadway segment(s) or traffic conditions [CVC
40802(c)(2)(B)(i)(II)]. These provisions ensure that posted speed limits are kept reasonably current.
This letter is to certify that I am the licensed and duly designated Traffic Engineer for the City of La
Quinta. I have evaluated six street segments that are part of the 2024 ETS. Attached is the resolution
adopting new speed limits and a copy of the E&T Study. Therefore, based on the above reasons, the
most recent Engineering and Traffic Survey shall be effective 30 days after the adopted date of the
particular ETS conducted for the following street segment:
• Dune Palms Drive from Mile Avenue to Fred waring Drive — 35 mph
If you have any questions, you may contact Mr. Bryan McKinney, Public Works Director at (760) 777-
7045 or myself, at (562) 364-8526.
Sincerely, DQRQFESSIp � O�?,OfESSI I
No. 91787 TR 2933
Nicolle Spann, P.E., T.E.
Traffic Engineer �If% C V k� �� �91� RA F f ■ o�s�
OF C A1-�F �F C A1.�F
Cc: City Attorney
City Clerk
Riverside County Sheriff's Department
Engineering I Geotechnical I Environmental I Sustainability I Financial I Homeland Security
562.908.6200 1 800.499.4484 1 fax: 562.695.2120 1 13191 Crossroads Parkway North, Suite 405, Industry, CA 91746-3443 1 www.wilidan.com
October 1, 2024
Mr. Bryan McKinney, P.E.
City Engineer
Public Works Department
City of La Quinta
78-495 Calle Tampico
La Quinta, CA 92253
1I�W 1 LLDAN
Subject: 2024 Engineering and Traffic Survey – Jefferson Street
Dear Mr. McKinney:
As requested, Willdan has completed a review of the recommended speed zone on one
segment of Dune Palms in the City of La Quinta. The Engineering and Traffic Study dated
January 5, 2017, is hereby amended to include the updated speed limit for the segment
listed below that supersede the previous speed limit recommendation.
27 — Dune Palms — Miles to Fred Waring
We are pleased to submit the enclosed recommendation and supporting documentation
for the above segment. The Engineering and Traffic Survey for the above segments were
conducted in accordance with applicable provisions of the CVC, following procedures
outlined in the California Manual on Uniform Traffic Control Devices (California MUTCD)
dated November 2014, and as required by Section 627 of the California Vehicle Code.
The Report is intended to satisfy the requirements of Section 40802 of the CVC to enable
the continued use of radar for traffic speed enforcement.
We appreciate the opportunity to serve the City of La Quinta, and the assistance and
cooperation afforded to us during the course of this study.
Very truly yours,
WILLDAN
Nicolle Spann, P.E., T.E.
Traffic Engineer
Enclosure
Engineering and Planning 1 Energy Efficiency and Sustainability Financial and Economic Consulting 1 National Preparedness and Interoperability
562.908.6200 1 800.499.4484 1 fax: 562.695.2120 1 13191 Crossroads Parkway North, Suite 405, Industry, California 91746-3443 1 www.willdan.com
I
Table 1
Table 2
IStreet
Segments with Recommended Speed Changes
NO
lim
STREET
POSTED NEW
FROM TO SPEED POSTED
LIMIT SPEED
LIMIT
CHANGE
27
Dune Palms
Miles Fred Waring 45 35
10 mph reduction
* See "Segments with Special Conditions" Section for Comments
2024 Engineering and Traffic Survey Amendment
City of La Quinta
Page 2
Table 2
•
Speed/Collision Data Summary Table
ID Street
Segment
Dist. 85% 10 Mi. % in Accident Rate
Posted
Speed
Limit
Prop.
Speed
Limit
Remarks
�Mi� Dir. Speed Pace Pace ADT Exp. Act.
27 Dune Palms
Miles to Fred
Waring
.48 N/S 42 33-42 81 4,876 1.24 0.00
45
35
* See "Segments with Special Conditions" Section for Comments
2024 Engineering and Traffic Survey Amendment
City of La Quinta
Page 2
SEGMENT WITH SPECIAL CONDITIONS
The following segment surveyed had recommended speed limits that were 5 miles per hour
(mph) or more below the critical speed due to conditions not readily apparent to the driver.
This segment is discussed below.
Segment 27 — Dune Palms — Miles to Fred Waring
This segment is currently posted at 45 mph and has one through lanes in each direction
with an ADT of 4,876 vehicles per day. The adjacent land is residential with some
commercial along the 0.48- mile -long segment. The 85th percentile speed is 42 mph and
would normally justify a 40- mph posted speed limit. This segment is identified as a land or
facility that generates high concentrations of bicycles and pedestrians. The segment has
bike lane and golf cart presence along the corridor and used by 3 schools in the area.
Because this segment is established as a land or facility that generates high
concentrations of bicycles and pedestrians, an additional 5 mph reduction can be applied.
It is recommended that the speed limit be posted at 35 mph for the above reasons. This
recommendation falls within the limitations requiring the recommendation be no more
than 12.4 mph under the 85th percentile speed.
2024 Engineering and Traffic Survey Amendment
City of La Quinta
Page 3
LEGEND:
SPEED LI16IIT IIPH
25
35
45
50
55
= CITY LIMIT
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CILLEGkR
CITY OF LA QUINTA
SPEED LIMITS
PREPARED SEPTEMBER 2424
RT.SS
MAK
CITY OF LA QUINTA
ENGINEERING & TRAFFIC SURVEY
STREET: Dune Palms Road
DATE: 9/29/24
between Miles Avenue
and Fred Waring Drive
TIME: 1:00 PM OBSERVER: Steve Libring
LOCATION: 27
PART I: HIGHWAY & ROADWAY CHARACTERISTICS
Sight Distance Obstructions?
(yes or no)
S/B
N/B
Notes
1. Horizontal
No
No
2. Vertical
No
No
3. Superelevation (%)
None
None
4. Shoulder Conditions (paved or unpaved)
Paved
Paved
5. Profile Conditions (grade,%)
6. Commercial Driveway Characteristics
(at grade, dustpan, etc)
At -Grade
At -Grade
Limited driveways on
each side of roadway
7. Pedestrian Traffic in the Roadway without
sidewalks (yes or no)
No
No
Sidewalks on both
sides
8. Adjacent Land Use
(residential, commercial, office, etc)
Residential &
Commercial
Residential &
Commercial
9. Intersection Spacing and Offsets
(spacing, feet -offsets, yes or no)
No offsets
Signals at Fred
Waring Drive and at
Miles Avenue
10. Pavement Condition
(good, satisfactory, poor)
New
New
11. Truck Traffic (heavy, moderate, light)
Light
Light
12. Channelization (# of lanes, divided,
undivided, painted, or raised median)
1 lane with bike/cart
lane, divided with a
painted median
1 lane with bike/cart
lane, divided with a
painted median
12' painted median
13. Street Width and Alignment
(width, feet — straight or curved)
64'
64'
14. Street Length
2,530 ft. segment
15. Average Daily Traffic
4,876 total - collected
9/10 thru 9/17/2024
16. Traffic Flow Characteristics
(heavy, moderate, light)
Light
Light
17. Uniformity with the Community
(yes or no)
Yes
Yes
18. Heavy On -Street Parking Turnover
(yes or no)
No
No
No parking allowed
on both sides
19. Street Lighting
Only at signals
STREET: Dune Palms Road
P
CITY OF LA QUINTA
ENGINEERING & TRAFFIC SURVEY
between Miles Avenue
and Fred Waring Drive
LOCATION: 27
Direction
Bi-directional
❑ Northbound *
❑ Eastbound *
❑ Southbound *
❑ Westbound *
RT II: PREVAILING SPEED MEASUREMENT
Location of Radar Measurement
Number of
Accidents
Midblock
0
Date of Radar Measurement
9/16/2024
Midblock
Accident Rate
(Acc/MVM)
Expected-Statewide/Year
Time of Radar Measurement (24 hour)
1:00 PM TO 2:00 PM
Actual
50%ile (mph)
85%ile (mph)
38
42
10 mph Pace (% of Vehicles)
33-42 (81%)
Posted Limit
Prevailing Limit
45 mph
45 mph
PART III: ACCIDENT RECORDS
Time Period Evaluated
1/1/2019 TO 12/31/2021
Number of
Accidents
Midblock
0
Midblock
Accident Rate
(Acc/MVM)
Expected-Statewide/Year
1.24 per MVM
Actual
0.00 per MVM
PART IV: ADDITIONAL REMARKS
High Bike and Ped Generators — 2 schools at Miles, one at Blackhawk
RECOMMENDED SPEED LIMIT
35 mph
* May be used in cases where two or more separate roadways are provided.
CERTIFICATION: I, Nicolle Spann do hereby certify that this Engineering and Traffic Survey within the City of La Quinta
was performed under my supervision and is accurate and complete. I am duly registered in the State of California as a
Professional Engineer (Traffic).
i// 10/1/2024 TE 2933
Nicolle Sp nn Date State Registration Number
CITY OF LA QUENTA
FOR ROADWAY: DUNE PALMS
SPEED
I' SIF
TOTAL VEHICLES SURVEYED
NORTHBOUND+SOUTHBOUND
NB
0
0
a
4
0
SB
O
O
O
0
0
TOTAL
VErix:i i ti
0
0
D
0
0
0
O
O
0
0
x
0
0
0
O
0
0
O
0
0
0
a
x
x
x
x
x
x
x
x
x
x
21 I
I I I I I I I I I
x
x
x
x
a
0
a
0
0
2
2
a
5
5
O
O
0
O
O
0
a
1
2
2
0
3
3
0
0
0
0
4
8
8
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
111 1 11 1 1 1 1 11 1 1 1 1 11
7
a
7
4
4
3
3
x
0
a
a
a
0
0
8
a
a
a
7
3
2
1
2
1
15
16
15
12
11
6
5
3
3
0
O
0
O
0
0
O
0
0
0
0
0
0
0
0
0
4
0
0
0
0
0
66
0
O
0
0
0
O
O
62
0
0
0
128
•
h
•
P
A
C
E
a
•
DATE: 09!26124 DAY: Thursday TIME PERIOD: 1 00 PM TO 2.00 PIV
LIMITS (BTN): Miles and Fred Waring
OBSERVATION POINT: Midway
POSTED SPEED LIMIT:
COMMENTS:
85TH %:
45 MPH OBSERVER: LIBRING
after new road diet WEATHER: SUNNY
ROAD SURFACE: DRY
ROAD CONDITION: GOOD
DATA COLLECTION METHOD: RADAR
NORTHBOUND SOUTHBOUND NORTHBOUND+SOUTHBOUND
42 41 42 M.P.H.
50TH %: 38 37 38 M.P.H.
15TH %: 34 34 34 M.P.H.
10 MPH PACE: 33 - 42 32 - 41 33 - 42 M.P.H.
% IN PACE: 82% 827., 81%
% OVER PACE: 12% 11% 12%
% UNDER PACE: 6% 5% 7°/a
ARITHMETIC MEAN: 39 37 33 M.P.H.
SAMPLE VARIANCE: 22 16 19
STANDARD DEVIATION: 5 4 4 1.1. H.
VARIANCE OF THE MEAN: 6.33 0.25 0.15
STD. ERROR OF THE MEAN: 0.58 0.50 0.39 M.P.: I.
W:IWE-CA1La Quinta, City ot'Dune Palms E&T Update - Oct 2024\ RADAR FORM - Oune Palms between Miles and Fred Waring