1 Date: 4/06/2023
Subject: Oakes Street, Pulgas Avenue, and Gaillardia Way Multi-Way Stop Sign Warrant Reanalysis To Whom It May Concern:
The City of East Palo Alto’s Engineering Division performed a multi-way stop sign re-analysis for the Oakes Street, Pulgas Avenue, and Gaillardia Way intersection. The attached report discusses the full reanalysis and based on the report we recommend a multi-way stop sign at this time.
The original analysis was completed in response to a resident’s request to verify if a multi-way stop sign installation is warranted. The residents written request may be found in Appendix E. The guidelines outlined in the California Manual of Uniform Traffic Control Devices (California MUTCD) were used for the analysis. Currently, there is a four-way intersection that is stop controlled on Oakes Street and Gaillardia Way. The original analysis was performed in 2021 and the re-analysis was performed in 2023.
In overall consideration of existing conditions, a multi-way stop sign is recommended.
Please let me know if you have additional questions about the analysis.
Sincerely,
Batool Zaro
Associate Engineer
[email protected]
City of East Palo Alto
Attach: Multi-Way Stop Control Warrants Analysis Report
CITY OF EAST PALO ALTO
PUBLIC WORKS DEPARTMENT
ENGINEERING DIVISION
1960 Tate Street, East Palo Alto, CA 94303 (650) 853-3189 2 MULTI-WAY STOP CONTROL WARRANT ANALYSIS REPORT
OAKES STREET & PULGAS AVENUE & GAILLARDIA WAY
IN THE CITY OF EAST PALO ALTO
INTRODUCTION
There have been some safety concerns brought up regarding the Oakes Street, Pulgas Avenue, and Gaillardia Way intersection due to its proximity to Joel Davis Park, and a multi-way (four-way) stop sign has been requested. This analysis is to verify if a four-way stop sign installation is warranted and recommended based on standard guidelines.
In 2021, the original analysis was performed and the warrant conditions were not satisfied. The City received additional verbal requests to re-analyze the intersection for a multi-way stop. Per the City’s residential street management policy, if the identified issue had previously been evaluated in the prior 18- month period, then the resident will be informed of the results of that previous evaluation. No further evaluation will be performed until additional time elapses, or the City Engineer determines a need has arisen or the City Council so directs. Since the 18-month period has elapsed, the intersection was reevaluated.
Current conditions consist of a four-way intersection. Pulgas Avenue runs in the north/south direction, Gaillardia Way runs in the east direction, and Oakes Street runs in the west direction. The location is demonstrated in Image 1 below. Oakes Street and Gaillardia Way are stop-controlled and Pulgas Avenue is uncontrolled. The intersection is within the City of East Palo Alto’s jurisdiction.
Image 1: Location Map, City of East Palo Alto
BACKGROUND
N
3 Pulgas Avenue is a neighborhood connector-collector street that runs in the north/south direction. Pulgas Avenue is the “major” street in this intersection. The speed limit on all streets is 25 mph. At the intersection, Pulgas Avenue is approximately 44 feet wide, and the 2-lane roadway is separated by centerline striping. Parking is permitted on both sides of the street; however, the north and south bound directions differ. The northbound direction side consists of rolled curb, sidewalk, and gutter. The southbound direction consists of curb, sidewalk, planters, and gutter. There are marked crosswalks across Oakes Street and the southern side of Pulgas Avenue at the intersection.
See Image 2 and Image 3 for photo images of Pulgas Avenue.
Image 2: Pulgas Avenue Looking North Image 3: Pulgas Avenue Looking South Oakes Street (the western direction of the intersection) is a neighborhood-local street that’s approximately 32 feet wide, and the 2-lane roadway provides one lane in each direction that is separated by centerline striping. On Oakes Street parking is allowed on both sides of the street. The roadway has curb, gutter, parkway, and sidewalk. There is a STOP sign, a white ‘STOP’ pavement marking, and a white limit line at the intersection. Pulgas Avenue is the easterly terminus of Oakes Street.
See Image 4 for a photo image of Oakes Street.
4 Image 4: Oakes Street Facing Pulgas Ave
Gaillardia Way (in the eastern direction) is a neighborhood-local street that’s an approximately 24 feet wide street with rolled curbs. The 2-way roadway is not separated by centerline striping. Gaillardia Way has rolled curbs where cars can park on both sides, sidewalk, and gutter. There is a STOP sign, a white ‘STOP’ pavement marking, and a white limit line at the intersection. Pulgas Avenue is the westerly terminus of Gaillardia Way.
See Image 5 for a photo image of Gaillardia Way.
Image 5: Gaillardia Way Street Facing Pulgas Ave
WARRANT GUIDELINES
5 The City of East Palo Alto follows State guidelines outlined in the California Manual on Uniform Traffic Control Devices (MUTCD) when determining if traffic control devices should be installed. The guidelines outlined in the California MUTCD were used for this analysis. The manual outlines minimum guidelines regarding traffic volumes, collisions, speed, visibility, and other criteria in order to warrant traffic control devices like the installation of a multi-way (4-way) stop sign in this case.
The California MUTCD application guideline criteria for a multi-way stop is described below:
1. As an interim measure where traffic control signals are justified. “Where the traffic control signals are justified, the multi-way STOP is an interim measure that can be installed quickly to control traffic while arrangements are being made for the installation the traffic control signal”.
2. Reported crashes – five or more in a 12-month period that are susceptible to correction by a multiway stop installation.
3. Minimum traffic and pedestrian volumes, speeds, and delay as outlined in Section 2B.07.
4. Where a combination of the above criteria are all satisfied to 80 percent.
When any one, or a combination of these criteria is met, then a multi-way stop application should be considered. A multi-way stop sign is usually not recommended when the criteria are not met. The California MUTCD guidelines described above are included in Appendix A.
MULTI-WAY STOP ANALYSIS
The California MUTCD outlines the guidelines describing the minimum collisions and traffic volumes necessary to warrant a multi-way stop sign. Engineering judgment must also be considered along with these guidelines. One important thing to note is that a stop sign will not stop the speeding issue; however, it might help guide vehicles to safely make their turns. Additional guidance criteria found in the manual include the following important statements: “YIELD or STOP signs should not be used for speed control… In most cases, the street carrying the lowest volume of traffic should be controlled…” Collision History
The guidelines in the California MUTCD outline that a minimum of (5) reported crashes occurring in a 12-month period that are susceptible to correction by a multi-way stop installation must occur in order to satisfy this warrant. The crashes include right-turn and left-turn collisions, as well as right-angle collisions and pedestrian-vehicle collisions.
The latest collision history was gathered by the City’s Engineering Division from the City of East Palo Alto’s Police Department (PD). A comprehensive 3-year traffic collision history summary report was prepared for this intersection and reviewed for collisions susceptible to correction by the installation of a multi-way stop. Table 1 demonstrates the most recent 3-year summary of collisions at this intersection.
TABLE 1
6 PD COLLISION HISTORY SUMMARY
2020 2021 2022
Intersection Date Type of
Collision
Date Type of
Collision
Date Types of
Collision
Oakes St &
Pulgas Ave
&
Gaillardia
Way
1/08/2020
5/25/2020
Sideswipe
Sideswipe
06/01/2021
08/31/2021
Sideswipe
Rear end
05/03/2022
11/27/2022
Rear end
Broadside
Notes: Information above is derived per the latest 3-year intersection traffic collision database report gathered from the East Palo Alto’s Police Department (PD).
As shown in Table 1 above, there have been six (6) reported collisions at or near this intersection over the past three (3) years. Since the collision warrant requires a minimum of five (5) reported crashes susceptible to correction by a multi-way stop, to occur within a 12-month period, the collision warrant is not satisfied. The EPA PD collision report is included in Appendix B.
Traffic Volumes
The City of East Palo Alto collected turning movement counts using the platform Streetlight Data The traffic volume data collected for this intersection is included in Appendix C.
Pulgas Avenue is considered the “major” street at this four-way intersection. Oakes Street and Gaillardia Way are considered “minor” streets since drivers are required to stop at Pulgas Avenue and look both ways before making a left or right turn. It is anticipated that the minor streets receive less traffic volume than the major street.
A part of the California MUTCD guideline criteria calls for a reduction in the required minimum volumes when the critical approach speed (or 85th-percentile speed) on the major street exceeds 40 MPH. If this is the case, the minimum vehicular volumes to be met for a multiway stop sign installation are reduced to 70%. As mentioned, the speed limits on all streets are 25 MPH. The platform Streetlight Data confirmed the vehicle speeds are greater than the 40 MPH limit required to reduce traffic volumes, the 70% minimum volumes for a multi-way stop sign analysis are applicable.
Table 2 below shows the California MUTCD minimum traffic volume criteria for a multi-way stop sign with the highest 8-hour traffic counts data for this intersection. Both Part 1 and Part 2 need to be satisfied in order to fulfill the traffic volume warrant.
TABLE 2
CA MUTCD MULTI-WAY STOP CRITERIA
Part 1:
The vehicular volume
entering the
and Part 2:
The combined vehicular,
pedestrian, and bicycle volume
but Part 3:
If the 85th -percentile
approach speed of the
7 intersection from the
major street approaches
(total of both
approaches) averages at
least 300 vehicles per
hour for any (8) hours
of an average day
Original Results:
No, does not meet 70%
of warrant
= 180 vehicles per hour
Update:
Yes, meets warrant
= 2455 vehicles/ 8
hours
=307 vehicles per hour
entering the intersection from the
minor street approaches (total of
both approaches) averages at least
200 units per hour for the same (8)
hours, with an average delay to
minor-street vehicular traffic of at
least 30 seconds per vehicle during
the highest hour.
Original Results:
Yes, meets 70% of warrant
= approx.145 per hour
Update:
Yes, meets 70% of warrant
= ((381 Peds 24 hours)+(400
Cyclists 24-hours))*0.15+(343
vehicles/8 hours) = approx.160 per
hour
major street traffic
exceeds 65 km/h or
exceeds 40 mph, the
minimum vehicular
volume warrants are (70)
percent of the above
values.
Original Results:
Yes, 85th percentile speed
on major street exceeds
40 mph
Update:
Yes, 85th percentile speed
on major street exceeds
40 mph
As shown above, the average hourly intersection traffic for the highest 8-hour period did satisfy both Part 1 and Part 2 when using 70% of the warrant values. Therefore, the minimum traffic volume warrant is satisfied. Since bicycle and pedestrian counts are only available for 24-hour periods, it’s assumed that the morning/afternoon peak is 15% of the total counts. The 85th percentile speed was found to be between 30- 40 mph, so the most conservative value was taken.
Visibility
On-site field visits were made to determine if there are restricted sight distances due to the geometry of the intersection and other potential obstructions. The driver sight distances were measured from the sidestreet approaches since they are required to stop before proceeding to make a left or right turn onto Pulgas Avenue. The minimum stopping sight distances are derived from the stopping sight guidelines in the California MUTCD (reference Appendix D). For a 25-mph street, a minimum stopping sight distance of 155 feet is required. The stopping sight distance was measured on the field from a “typical” vehicle stopped location at Oakes Street and Gaillardia Way looking for traffic approaching on Pulgas Avenue.
An orange cone was placed to mark the distances and photos were taken.
Image 7 demonstrates that when looking from Oakes Street, the driver only has a clear line of sight looking south (looking right) on Pulgas Avenue when no vehicles are parked. When looking north (looking at the left direction), the driver’s line of sight is obstructed by parked vehicles and a clear line of sight is available when the drivers encroach the sidewalk (as demonstrated in Image 6). 8 Image 6: Oakes Street Facing Pulgas Ave (Looking North) Image 7: Oakes Street Facing Pulgas Ave (Looking South) 155 feet
155 feet
9 Image 8 demonstrates how when drivers are stopped on Gaillardia looking south (looking in the left direction), the line of sight is obstructed by parked vehicles. A clear line of sight is only possible when the driver drives past the white marked stop line and closer to Pulgas Avenue. Image 9 demonstrates that when looking north (looking in the right direction) the line of sight is clear when no vehicles are parked along Pulgas Avenue.
Image 8: Gaillardia Way Street Facing Pulgas Ave (Looking South) Image 9: Gaillardia Way Street Facing Pulgas Ave (Looking North) 155 feet
155 feet
10 MULTIWAY STOP ANALYSIS SUMMARY
The guidelines are: 1. As an interim measure where traffic control signals are justified; 2. Reported crashes – five or more in a 12-month period that are susceptible to correction by a multi-way stop installation; 3. Minimum traffic and pedestrian volumes, speeds, and delay as outlined in Section 2B.07;
4. Where a combination of the above criteria are all satisfied to 80 percent.
In summary, the collision history gathered resulted in six (6) accidents in the last three years. The minimum guideline calls for at least five (5) accidents within a 12-month period. Condition 2 is not satisfied because less than (5) crashes occurred at this intersection during a 12-month period.
The average minimum hourly volumes were satisfied as demonstrated in Table 3; therefore, condition (3) is satisfied.
Engineering judgment is also considered part of the warrant analysis. It was determined that the obstructed sight triangles not only impact the safety of vehicles making right/left turns, but it also impacts pedestrians because drivers on Pulgas Avenue are also unable to see pedestrians. As part of the original analysis, parking restrictions were recommended instead of the multi-way stop. However, during the reanalysis, staff found higher traffic volumes and an increase in collisions. Although the reported accidents do not satisfy condition (2), since the parking restrictions have not been implemented and conditions have changed, staff is recommending the installation of the multi-way stop at the intersection.
RECOMMENDATION
A multi-way stop sign installation is recommended for this intersection. The analysis demonstrates that speeding issues combined with the impaired sight triangle raise some safety concerns. Vehicles parked along Pulgas Avenue block drivers from being able to see pedestrians crossing from Gaillardia Way to Oakes Street. Installing a multi-way stop would help vehicles make their turns safely.
MULTIWAY STOP ANALYSIS SUMMARY
After overall analysis, a multi-way (4-way) stop sign installation is recommended at this time for Oakes Street, Pulgas Avenue, and Gaillardia Way.
11 APPENDIX A
MULTIWAY STOP APPLICATIONS
GUIDELINES: CALIFORNIA MUTCD
12 13
14 15
APPENDIX B
POLICE DEPARTMENT COLLISION HISTORY REPORT
CITY OF EAST PALO ALTO JEFF LIU
POLICE DEPARTMENT INTERIM CHIEF OF POLICE
141 Demeter Street (650) 853-5904 Phone
East Palo Alto, CA 94303 [email protected]
_________________________________________________________________ Vehicle Accidents at the Intersections of
Pulgas Avenue, Gaillardia Way and Oakes Street in East Palo Alto January 1, 2020 – December 31, 2022 (3 years)
There was a total of six (6) vehicle accidents at the intersections of Pulgas Avenue, Gaillardia Way and Oakes Street in East Palo Alto from January 1, 2020, through December 31, 2022. This information is limited in that it only covers the accidents that were either reported to or discovered by the police. These numbers are not all inclusive as they do not include accidents that were not reported to the police department, reports made to the Department of Motor Vehicles, and reports made to insurance companies.
For more complete statistics please reference the Statewide Integrated Telecommunications System. 1 For further details on the accidents, please refer to the attached excel spreadsheet.
1 Statewide Integrated Telecommunications System (SWITERS) is maintained by the California Highway Patrol and information can be accessed online. http://www.chp.ca.gov Numbers are subject to change as accidents may have been reported after the date the data was pulled on 02/28/2022.
16 APPENDIX C
TRAFFIC VOLUMES
COUNT DATA
17 APPENDIX D
CALIFORNIA MUTCD STOPPING SIGHT GUILDELINES
18 19
APPENDIX E
MULTI-WAY STOP SIGN ANALYSIS REQUEST
2 From: Humza Javed <[email protected]>
Sent: Sunday, January 31, 2021 10:13 PM
To: Amy Chen <[email protected]>;
Subject: Re: Stops at oakes and gallardia and pulgas
Thanks for your question. Stop controlled intersections need to meet certain state standard criteria. We will run a Stop warrant analysis at this intersection and provide a response to you within a few weeks.
Please do not hesitate to contact me with any further questions.
Thank you
Humza Javed
From: Amy Chen <[email protected]>
Sent: Sunday, January 31, 2021 12:20 PM
To:
Cc: Humza Javed <[email protected]>
Subject: RE: Stops at oakes and gallardia and pulgas
Hello
Thank you for your email. I am adding our City Engineer here as he may be able to better address your inquiry.
Amy Chen
Director of Community and Economic Development
City of East Palo Alto
1960 Tate St
East Palo Alto, CA 94303
(650) 853‐3193
[email protected]
From:
Sent: Saturday, January 30, 2021 10:09 AM
To: Amy Chen <[email protected]>
Subject: Stops at oakes and gallardia and pulgas
Hello I am a resident in the pulgas ave area and for years I have been asking for a cross walk to be made on the street of pulgas and Galleria, and oakes. We got it done two years ago but my biggest concern is that there is no stop sign to help children crossing my request is that there please make this a 4 way stop street like all other school/park zones the red circles are where we have stop signs, the yellow is where I'm requesting to get them done. In conclusion I believe this will help pedestrians cross safely especially because there are bus zone in this street thank you. 3 Waiting for response
1952 pulgas Ave, East Palo Alto, CA 94303
Phone number
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