2022 Safe Streets Evaluation Summary

San Francisco adopted Vision Zero in 2014, a citywide and inter-departmental commitment to prioritize street safety and eliminate traffic deaths in San Francisco.

Data-driven analysis is at the core of San Francisco’s Vision Zero program, allowing the city to cost-effectively prioritize limited resources. As part of that data-driven approach, SFMTA maintains a robust Safe Streets Evaluation Program to measure the outcomes of safety investments. This evaluation summary provides an overview of the impacts of recent SFMTA street projects on safety and other metrics.

The SFMTA tracks and reports on the transformation of city streets in several ways The San Francisco Vision Zero program maintains a  quarterly dashboard   that details the number of safety measures installed across the city measured against commitments made in the San Francisco Vision Zero Action Strategy.

Additionally, the Safe Street Evaluation Program individually evaluates before and after conditions on many of our pedestrian, bicycle, and traffic safety projects, to ensure that we are not only delivering a certain quantity of improvements, but that those improvements are having the intended impact on improving safety. Since 2018, the Evaluation Program has published annual reports summarizing evaluation results for individual projects. Past annual reports can be found on the Program’s  webpage .

Instead of focusing on specific projects, this annual report reviews changes in key performance metrics across many of SFMTA projects completed in the past five years to identify the types of treatments and investments with the largest benefits. As the SFMTA continues to increase the pace of transportation safety investments, this analysis will help to ensure that those investments are well-spent and lead to measurably improved safety on San Francisco streets.

The projects that were analyzed for 2022 Safe Streets Evaluation Summary include both quick-build projects, or reversible, adjustable traffic safety improvements that can be installed relatively quickly, and capital projects, or large-scale construction projects that typically involve concrete/utility work and have long timelines and large budgets. The evaluated projects are listed below.

• 7th Street Safety Project – Phase 1 (Quick-Build)    
• 8th Street Safety Project (Quick-Build)      
• Folsom Streetscape Project (Quick-Build)
• Golden Gate Avenue (Quick-Build)
• Leavenworth Street (Quick-Build)
• Turk Street Safety Project (Quick-Build)     
• Central Embarcadero (Quick-Build)
• Valencia Bikeway Project (Northern Section Pilot/Quick-Build)
• 6th Street Pedestrian Safety Project (Quick-Build)
• Safer Taylor Street (Quick-Build)
• Indiana Street Bikeway Project (Quick-Build)
• California Street Safety Project (Quick-Build)
• Page Street Neighborway (Quick-Build)
• Fell Street Protected Bike Lane (Quick-Build)
• Polk Streetscape (Capital Project)
• Second Street Improvement Project (Capital Project)
• Masonic Streetscape Project (Capital Project)
• Left-Turn Traffic Safety at Seven Intersections (City-Wide Program)

Take a tour of each of these projects below!

Each of these evaluated projects included significant safety changes such as vehicle travel lane removals (road diets),  separated bikeways, separated bike signals, left-turn safety devices, and general improvements for pedestrians at intersections including pedestrian signal improvements, daylighting (red zones at intersections) and upgraded crosswalks.

Click through the photos below to find out more about these safety tools!

To understand if and how well these safety tools are working, the following key performance metrics were aggregated across the evaluated projects:

• Vehicle, Bicycle, and Pedestrian Collisions
• Vehicle Speeds
• Bicycle Volumes
• Bicycle Signal Compliance/Yielding
• Blockage of Bikeways
• Vehicle-Pedestrian Interactions
• Vehicle Travel Time
• Vehicle Turning Speeds

As part of reviewing the aggregated data over the past five years, we overwhelmingly found the SFMTA's safety tools are working.

Among the evaluated projects with at least three years of police report data, collisions decreased by 18%. Bicycle -related collisions experienced a more significant decrease of 33% and pedestrian-related collisions decreased by 32%. Looking specifically at our capital projects- pedestrian collisions have decreased on average by 50%.

The 85th percentile speed, or the speed at or below which 85 percent of the drivers travel on a road segment, decreased across projects by 3%, The greatest decrease in 85 ^th  percentile speed occurred on 6 ^th  Street, where speeds decreased by 20%. Even small decreases in speed are valuable safety improvements as vehicles speeds directly affect the severity of injuries.

Bicycle volumes grew sizably across the board, with increases up to 75% in the morning peak commute times, with similar growth in the afternoon peak commute times. On the two streets that had no bike facilities at all before the project (2 ^nd  Street and Masonic Avenue), bicycle volumes are up significantly.

Separated bicycle signals installed across the evaluated projects are providing major safety benefits by lowering vehicle-bike interactions at the location of the signal/turn by 93% on average, with a 62% decrease in near-misses or close calls. Moreover, both vehicles and bicycles are complying with the bicycle signals (87% compliance by bicycles, 90% compliance by vehicles). Interactions are defined as instances when turning vehicles and bicycles are near each other and one party must yield to the other.

Data from the evaluated projects demonstrates with certainty that providing protected bikeways provides significant decreases in vehicle blockage of the bike lane. The rate of incidents of vehicles blocking the bike lane decreased by 90%.

The many pedestrian safety tools implemented at intersections including countdown signals, more walking time, daylighting and crosswalk upgrades are helping to not only decrease pedestrian-related collisions, but also close calls at crosswalks. While the number of interactions between pedestrians and vehicles generally increased at intersections (expected when implementing measures such as turn restrictions where more vehicles are turning during the green light), close calls or near misses decreased across projects by 38%.

While vehicle travels times are not indicative of improvements to safety, they can be important in understand the cost-benefit to safety projects as it relates to overall traffic congestion and emergency response time. Even with the 7.3 miles of road lane reductions implemented across the evaluated projects, the average vehicle travel time during peak periods increased on average by approximately 50 seconds.

Overall, the seven intersections piloted in early 2021 for left-turn traffic safety treatments resulted in an approximately 17% reduction in average turning speed (1.7mph slower) and a 71% reduction in the likelihood of a car turning left at speeds over 15 mph.

Due to these encouraging results, left turn safety treatments will become a key tool in SFMTA’s future street improvement projects.

To get these results, the SFMTA utilized data collected from 17 projects and one pilot program for left turn safety treatments - all completed over the last five years. We reviewed hundreds of police-recorded collision reports, speed data collected through pneumatic tubes, and hours of anonymized observations by objective third parties. Projects were selected based on sufficient data available and generally represent the wide range of treatments installed by the SFMTA, and several include both success stories and less successful safety components such as partially protected bike lanes. Annual collision rates were derived from three years of pre-implementation data to determine baselines, and from at least one year of post-implementation data.

Performance metrics were selected based on national best practices, and commonly collected data such as speeds and volumes. For many of the metrics, specific templates and standard operating procedures (SOPs) have been developed to ensure consistent data collection even when observing qualitative metrics such as yielding and near misses or “close calls”. To find out more about our evaluation process please see our  Safe Streets Evaluation Handbook.  

The  Vision Zero Quick-Build  initiative is an SFMTA effort to quickly implement pedestrian and bicycle safety improvements on the Vision Zero High Injury Network. Quick-Build projects are reversible, adjustable traffic safety improvements that can be installed relatively quickly. Unlike major capital projects that may take years to plan, design, bid and construct, quick-build projects are constructed within weeks or months and are intended to be evaluated and reviewed within the initial 24 months of construction.

Typical quick-build type improvements include:

• Paint, traffic delineators, and street signs
• Parking and loading adjustments
• Traffic signal timing
• Transit boarding islands

With the body of projects evaluated for the 2021 Safe Streets Evaluation Summary, 14 of the projects are near-term or quick-build projects and three are major capital projects that were implemented within a much longer timeline.

Below is a matrix comparting aggregate metrics between the capital projects versus the evaluated Quick-Build projects.

Because the overall collision rates do not take into account increased bicycle ridership, it is also helpful to look specifically at the three capital projects (2nd Street, Masonic Avenue, and Polk Street) to understand the collision rates side by side with bicycle volumes.

Capital projects show strong results with a 50% decrease in pedestrian collisions. The greater pedestrian safety for the capital projects (50%) versus quick-builds (26%) is likely due to building more concrete features such as widened sidewalks and bulb-outs. While bike related collisions for the capital projects did not decrease on average (-5%) as much as quick-build projects (-42%), the collision rate does not take into account large increases in the number of bicyclists on the capital projects. In fact, on two streets that had no bike facilities in the pre-condition (2 ^nd  Street and Masonic Avenue), bicycle volumes are up significantly. The three capital projects observed also included minimally protected bike lanes and trials in design such as partially raised cycle tracks. The SFMTA has learned from these older projects and has since invested in capital projects such as   Folsom and Howard Streets   which include not only concrete upgrades for pedestrians, but fully protected bike infrastructure as well as public realm upgrades.

But quick-builds still provide and enormous amount of benefit. Quick-builds are implemented swiftly and cost a fraction of the cost of large capital project, yet are leading to significantly less collisions, slower speeds, and less close calls.

The major takeaway is that both capital and Quick-Build projects have resulted in major safety benefits. Given the timeline and costs of large capital projects, installing Quick-Build projects before making improvements permanent through a full capital improvement is a very effective strategy for addressing immediate safety needs on city streets.

The SFMTA recognizes our involvement in the long history of past racist policies that have led to disinvestment in some communities within San Francisco. Rectifying these injustices will take time, but begin with near-term efforts in underserved areas such as the recently completed  Bayview Quick-Build  in Hunters Point/Bayview, the Leavenworth and Golden Gate Quick-Build projects in the Tenderloin, and the neighborhood-wide No Turn on Red turn restriction effort in the Tenderloin. The goal of this work by SFMTA staff is to begin the process of building trust with community members, uplifting their voices, and ultimately decreasing traffic violence in previously underserved communities.

A major goal of the  Bayview Quick-Build Project  is to improve pedestrian visibility and comfort at crossings and reducing vehicle speeds. To date, improvements identified by the community through the  Bayview Community Based Transportation Plan  have been installed on Evans Avenue, Hunters Point Boulevard, and Innes Avenue. Changes to the roadways included a lane removal from four lanes to two lanes on a section of these roadways to include one bike lane and walkways on both sides of the street protected by concrete barriers, new turn pockets on Innes Avenue, and new crosswalks, and protected corners at Jennings and Hawes Streets.

Data collected after this project shows verified improvements in driver yields at the Innes/Griffith (westbound) and Innes/Hunters Point (southbound) crosswalks, but there was no significant change to vehicle speeds. While the project entailed a detailed, community driven design and implementation process, the SFMTA needs to continue working with neighbors to make additional changes that build trust and further traffic  safety goals.

Stemming from the community’s demand for increased investment and broader solutions for traffic safety in the Tenderloin neighborhood, the SFMTA recently installed two quick-build projects in the neighborhood on Leavenworth Street and Golden Gate Avenue and will continue to further community discussion on future potential quick-builds on additional Tenderloin streets.

The Leavenworth Street Quick-Build included:

• Vehicle travel lane removal (three lanes to two) with narrow buffers to deter speeding and overtaking of vehicles
• Pedestrian safety improvements such as advanced limit lines, crosswalks, and painted safety zones at key intersections
• Reallocating curb space for residents’ and businesses’ parking and loading needs

Key findings from the project evaluation include:

• On average, there was a 12% decrease in double parking instances on Leavenworth at observed locations
• There was a slight increase in drivers yielding to pedestrians at observed intersections. 
• North and southbound weekday bike volumes have increased by 9% after project implementation (from 257 to 279 in peak periods)

 The Golden Gate Avenue Quick-Build included:

• Installation of a protected bikeway from Polk to Market street
• Installing an active flex space for local businesses and organizations to utilize
• Reallocating curb space for residents’ and businesses’ parking and loading needs

 When comparing pre- and post-data, we found that:

• Travel times decreased on average by 58 seconds, with the greatest decrease taking place in the AM peak period, where travel times decreased by over 50%.
• Instances of bike lane blockages on the weekdays reduced by over 90 percent. However, with the parking protected bikeway design, double parking in the travel lane became more prevalent.
• Bike counts increased by 29 percent (from 188 to 243 bikes) following the installation of the project. 

Given the high volume of high injury corridors and intersections in the Tenderloin, there is a clear need for not only street-specific interventions but also neighborhood wide countermeasures to help make these streets safer for all users. In Fall 2021, the SFMTA posted No Turn On Red signs at over 50 intersections in the Tenderloin to study how they can make streets safer to cross.

Findings from a before/after study reveal that No Turn on Red (NTOR) restrictions can keep crosswalks clear and reduce close calls on major intersections:

• Motorists are demonstrating a high compliance with NTOR restrictions. On average, 92% of vehicles are complying with the turn restriction.
• While pedestrian-vehicle interactions increased (expected given NTOR restriction), close calls for vehicle-pedestrians decreased from 5 close calls before NTOR signs were posted to 1 close call after restrictions were in place at observed intersections.
• Vehicles blocking or encroaching onto crosswalks on a red signal was reduced by more than 70% after the restriction was implemented.

The SFMTA has started to invest more in previously neglected neighborhoods, and we recognize there is more work to be done to continue to increase traffic safety and build trust. Towards this effort, the SFMTA has initiated several projects that are currently in planning and design. These include additional changes/amplified efforts in the Bayview, projects on Evans Avenue and Bayshore Boulevard, and a future quick-build on Hyde Street in the Tenderloin.

We plan to continue this work, while making new efforts to use new technology to improve accessibility to the evaluation data. Improvements include building a publicly accessible database of all data collected through the program, reviewing opportunities to better engage community stakeholders in our evaluation efforts, and distributing updates on our evaluation progress.