California Safe Speeds Toolkit: Real-World Examples and Self Quiz

Table of Contents

1. Sacramento Vision Zero: Reducing School Speed Zones

Details for Sacramento Vision Zero: Reducing School Speed Zones

Location:Sacramento, CA
Jurisdiction:City of Sacramento Department of Public Works, in coordination with the Police Department, the school districts, and the City Council offices.
Timeframe:Since 2019
Topic:15 mph school zone speed limit
Project Name:Sacramento Vision Zero: Reducing School Speed Zones
Scope:225 road segments near 115 schools

Key Considerations: 

  • Local jurisdictions can systematically implement 15 mph school zones that are compliant under the CVC and radar enforceable. 

  • A citywide implementation of 15 mph school zone speed limit where qualified can be effectively implemented and consistently communicated to the public.   

  • To remain consistent with the provisions of CVC § 627, the City of Sacramento collected the speed and volume data of each segment of roadway. 

  • The City of Sacramento’s implementation consisted of 368 sign installations and was estimated to cost $63,000 using the City’s Vision Zero Safety Program fund. 

The City of Sacramento’s citywide effort to reduce school zone speed limits to 15 mph and extend 25 mph school zones improves traffic safety, especially for children around schools. The City of Sacramento’s 2018 Vision Zero Action Plan “identified high speeds as the leading cause of traffic-related injuries and fatalities” (City of Sacramento 2023). The City also found that 83 schools in Sacramento were on the High Injury Network (HIN). 

Using AB 321 (2008), the City of Sacramento implemented 15 mph school zone speed limits and/or 25 mph extended school zone speed limits across 225 road segments near 115 schools. According to the City’s Administration Report, the implementation consisted of technical analysis from January to May 2019, City Council approval in June 2019, and the installation of 368 signs and 71 new signposts by February 2020. The estimated cost of sign installation was $63,000. 

Links to websites and documentation: 

2. San José Business Activity Districts 

Details for San Jose Business Activity Districts

Location:San José, CA
Jurisdiction:San José Department of Transportation
Timeframe:2021
Topic:Business Activity District (AB 43)
Project Name:San José Business Activity Districts
Scope:6 streets

Key Considerations: 

The City of San José identified speeding as the “top known cause of fatal and severe injury crashes” and is dedicated to using all available tools to reduce top speeds (City of San José 2022). Upon the passage of AB 43, San José implemented business activity districts as stipulated under the new law. Using the criteria under CVC § 22358.9, San José identified 6 eligible corridors in business activity districts and reduced their speed limit from 25 mph to 20 mph. As shown in the table below, all 6 eligible corridors met the retail/dining use requirement and had on-street parking. All but one corridor has signals or stop signs at intervals no more than 600 ft. 

Eligible corridors for 20 mph business activity district speed limit implementation

Retail or
Dining

On-street
Parking

Signals/Stop Signs
w/in 600 feet

Crosswalks
(uncontrolled)
Almaden Av: St. John St - Santa Clara St Yes Yes Yes
Evergreen Village Square Yes Yes Yes
Jackson St: 3rd St - 7th St Yes Yes Yes
Post St: Market St - 1st St Yes Yes Yes
Santa Clara St: Almaden Ave - 5th St Yes Yes Yes
Willow St: Palm St - Almaden Ave Yes Yes Yes Yes

Source: Adapated from City of José (City of San José 2022(link is external))

San José conducted outreach for its business activity district speed limits at their Transportation and Environment Committee and Vision Zero Task Force meetings in Spring 2022. The proposed speed limits were approved by the City Council on June 28, 2022. The signs were installed and the new speed limits were in effect by the end of 2022. San José also conducted education and outreach to residents and businesses on these new speed limits. 

Links to websites and documentation: 

  • City of San José blog post on 20 mph Business Activity District speed limits (City of San José 2022)

  • Memorandum for establishing 20 mph business activity district speed limits (Ristow 2022)  

  • Resolution to establish 20 mph business activity district speed limits (City of San José 2022)  

3. San Francisco Tenderloin Speed Limits and No Turn on Red

Details for San Francisco Tenderloin Speed Limits and No Turn on Red

Location:San Francisco, CA
Jurisdiction:San Francisco Municipal Transportation Agency (SFMTA)
Timeframe:Since 2021
Topic:Neighborhood-wide speed limit reduction
Project Name:Tenderloin Speed Limits and No Turn on Red
Scope:17 corridors

Key Considerations: 

  1. Local jurisdictions may be able to reduce the posted speed limit through the Engineering & Traffic Survey process and use of provisions under CVC § 22358.6

  2. Local jurisdictions can complement speed limit changes with signal retiming, turning restrictions, and other traffic calming efforts as a comprehensive effort to improve traffic safety.

  3. Communications team/staff play an important role in increasing safety awareness and educating road users on the new speed limits. 

San Francisco’s Tenderloin Speed Limits and No Turn on Red project is a neighborhood-wide effort that combines safe speeds, safe road design, and a communications campaign. The project addressed the disproportionately high serious and fatal crash rates in the Tenderloin District, a neighborhood in which every street is a part of the City’s High Injury Network (City of San Francisco 2023). 

The project consisted of reducing the speed limit on 17 corridors from 25 mph or higher to 20 mph using provisions included under CVC § 22358.6. Alongside the reduced speed limits, the City used a comprehensive approach to address traffic safety and advance Vision Zero that included the following: 

  • Prior efforts in lighting improvements and signal retiming (San Francisco Municipal Transportation Agency 2021).

  • Installation of new speed limit signs on each block, along with electronic signage at key locations.

  • New “No turn on red” regulations at 50 intersections. 

  • A multilingual advertising campaign that included digital ads, bus shelter posters, and light pole banners to alert drivers to the change

The implementation of the reduced speed limits included public outreach and was approved by the SFMTA Board of Directors in March 2021. The reduced speed limits were made possible by speed surveys that indicated that travel speeds warranted a 20 mph speed limit (San Francisco Municipal Transportation Agency 2021). 

SFMTA evaluated 9 corridors throughout the city (including 1 in Tenderloin) on which new 20 mph speed limits were implemented. For most of these 9 corridors, the median travel speeds were below 20 mph both before and after the speed limit reduction. The evaluation found no changes to the average median vehicle speeds across these corridors after the speed limits were reduced to 20 mph.  

Links to websites and documentation: 

4. Self Quiz on Example Scenarios  

Note: for the purposes of this self-quiz, assume all plans are to be implemented on or after June 30, 2024.

  1. A local municipality is hearing complaints about speeds on an arterial with many retail shops and restaurants. The road currently has a speed limit of 25 mph. Can the speed limit be lowered?

Answer: If the road can be established as a business activity district, the prima facie speed can be set at 20 mph in accordance with AB 43. 

  1. A local police department is deciding how to allocate resources for speed enforcement and are considering enforcement on a collector road that does not have a prima facie speed limit. The E&TS survey that was used to establish the current speed limit on the road was conducted 12 years ago and was evaluated by a registered engineer. Should the police department assign officers to perform radar speed enforcement on this road?

Answer: Yes, the police may use this road for court-justifiable radar speed enforcement since AB 43 extends the validity of an E&TS required for such efforts from 7 years to 14 years. NOTE: This requires that no significant changes in roadway or traffic conditions have occurred, including changes in adjoining property or land use, roadway width, or traffic volume.

  1. a) A local jurisdiction is concerned about the current posted speed limit on a roadway. There have been few serious or fatal crashes on this roadway, and there are very few bicyclists or pedestrians present. Utility poles carrying electrical wires run along the roadway and the incline on a certain section of the highway is very severe so that driver sight distance is limited significantly. If the 85th percentile speed turns out to be 37.4 mph, what is the lowest speed limit that can be set?

Answer: The lowest speed limit to set is 30 mph (for a total 7.4 mph reduction). First, round down to 35 mph (the nearest 5 mph increment). Then, reduce by another 5 mph for the unsafe roadside conditions created by severe sight distance limitations in close proximity to the utility poles.

b) A local jurisdiction is concerned about the current posted speed limit on a roadway.There have been few serious or fatal crashes on this roadway, and there are very few bicyclists or pedestrians present. Utility poles carrying electrical wires run along the roadway and the incline on a certain section of the highway is very severe so that driver sight distance is limited significantly. If the 85th percentile speed turns out to be 37.5 mph, what is the lowest speed limit that can be set?

Answer: The lowest speed limit to set is 35 mph (for a total 2.5 mph reduction). Round up to 40 mph, and then reduce by 5 mph for roadside conditions not readily apparent to the driver. OR  Round down to the nearest 5 mph increment rather than up.

c) A local jurisdiction is concerned about the current posted speed limit on a roadway. They have noted a high number of serious injury crashes on the roadway and a few fatalities. Additionally, utility poles carrying electrical wires run along the roadway and the incline on a certain section of the highway is very severe so that driver sight distance is limited significantly. If the 85th percentile speed turns out to be 37.4 mph, what is the lowest speed limit that can be set?

Answer: The lowest speed limit to set is 25 mph (for a total 12.4 mph reduction). First, round down to 35 mph (the nearest 5 mph increment). Then, reduce by another 5 mph for the unsafe roadside conditions created by severe sight distance limitations in close proximity to the utility poles. THEN, Reduce by another 5 mph for a Safety Corridor (with documentation provided).

d) A local jurisdiction is concerned about the current posted speed limit on a roadway. They have noted a high number of serious injury crashes on the roadway and a few fatalities. Additionally, utility poles carrying electrical wires run along the roadway and the incline on a certain section of the highway is very severe so that driver sight distance is limited significantly. If the 85th percentile speed turns out to be 37.5 mph, what is the lowest speed limit that can be set?

Answer: The lowest speed limit to set is 30 mph (for a total 7.5 mph reduction). Round up to 40 mph, and then reduce by 5 mph for the unsafe roadside conditions created by severe sight distance limitations in close proximity to the utility poles. OR  Round down to the nearest 5 mph increment rather than up. THEN, Reduce by another 5 mph for a Safety Corridor (with documentation provided).

  1. A local roadway has experienced a significant number of serious motor-vehicle crashes involving bicycles over the years. A recent engineering and traffic survey identified the 85th percentile speed on this road to be 49.9 mph. To best protect vulnerable road users, what is the lowest speed limit that can be set by the municipality? 

Answer: The lowest speed limit to set is 40 mph (for a total 9.9 mph reduction). First, elect to round down to 45 mph rather than up to 50 mph. Then, take another 5 mph reduction if the road is designated as a Safety Corridor (with documentation provided).

  1. A 4-lane local road in a downtown business district has a current speed limit of 35 mph. This road carries very high levels of pedestrian and bicycle activity and has experienced a significant number of serious motor-vehicle-related crashes over the past 3 years. What speed limit should be established on this road if the road is classified as a business activity district per AB 43 (including a maximum 30 mph speed limit on both approaches)? 

Answer: Could choose between 20 or 25 mph per AB 43. NOTE: Probably would want to strongly consider 20 mph given the high incidence of crashes and high concentrations of vulnerable users.

  1. a) A 4-lane local road has a currently posted speed limit of 35 mph. The previous posted speed limit was 30 mph but had to be changed when the 85th percentile from the last E&TS was measured at 32.8 mph. The city engineer performs a new E&TS because their old one is expiring and finds a new 85th percentile speed of 37.5 mph, which would round up to 40 mph, which seems concerningly high. What is the lowest speed limit that can be established on this roadway?

Answer: The lowest speed limit to set is 30 mph. This is allowable because this is the immediately prior speed limit. NOTE: This can only be done if no general purpose lanes have been added. ALSO NOTE: The speed limit could be set at 35 mph, retaining the current limit

b) A 4-lane local road has a currently posted speed limit of 35 mph. The previous posted speed limit was 25 mph by had to be changed when the 85th percentile from the last E&TS was measured at 32.8 mph. The city engineer performs a new E&TS because their old one is expiring and finds a new 85th percentile speed of 37.5 mph, which would round up to 40 mph, which seems concerningly high. What is the lowest speed limit that can be established on this roadway? 

Answer: Still, the lowest speed limit to set is 30 mph. The immediately prior speed limit of 25mph is over 5 mph below the currently posted limit of 35 mph, but only 5 mph maxiumum can be deducted. NOTE: This can only be done if no general purpose lanes have been added. ALSO NOTE: The speed limit could be set at 35 mph, retaining the current limit.

Disclaimer 

This Toolkit does not constitute a standard, specification, or regulation. This Toolkit is not intended to replace the existing Caltrans mandatory or advisory standards and is not intended to be a substitute for engineering knowledge, experience or judgment. This Toolkit promotes better access to helpful information and concepts from various agencies and organizations. UC Berkeley and Caltrans acknowledge the existence of other practices and provide this Toolkit for reference and direction for those responsible for making professional engineering or other design decisions. 

Please be aware that neither UC Berkeley nor Caltrans is the author of the external sources contained in this Toolkit and are therefore not responsible for errors or omissions that may be contained within those external sources. The references contained in this Toolkit are provided for the user’s convenience. The content or information in such references is the sole responsibility of their respective authors and/or owners.