Frequently Asked Questions

California Street Safety Project

Why are you implementing a road diet on this stretch of California Street between Park Presidio and Arguello?

On this stretch of the corridor, there have been 57 injury collisions in the past five years. This segment of California Street also has a high rate of Muni-involved collisions, with 35 transit collisions in five years. At 8 to 9 feet wide, the

travel lanes are not wide enough in this area for Muni vehicles, which are 10.5 feet wide, including mirrors. As a result, Muni vehicles must straddle multiple lanes, leading to sideswipe collisions. In addition, having multiple lanes in each direction can encourage higher traffic speeds and can make crossing the street more challenging for pedestrians.

All Quick-build projects are built with elements that can be removed or adjusted if needed. The SFMTA will be evaluating the impacts of the project over a 24-month period, to ensure that safety goals are being met and that vehicle traffic changes do not slow down Muni service. Adjustments can be made to address any issues that are identified during the 2- year evaluation phase of the project after it is implemented.

What is a road diet?

A road diet is a traffic safety measure that is widely used in San Francisco and across the country. Similar road diets that convert four lane street to a three lane street with a center turn lane have shown an 19-47% reduction in collisions, according to the Federal Highway Administration. A local example of an effective road diet on 25* Avenue in the Richmond reduced collisions by about 20%, while a road diet on Fulton Street between Central and Stanyan reduced collisions by 43%.

Can this new road design handle all the traffic on California Street?

San Francisco has experience with successful road diets on streets with similar volumes to California. By providing a center turn lane, which keeps turning vehicles from stopping other traffic, the roadway can function with close to the same capacity as it does today. California Street carries about 16,000 vehicles per day, while road diets have been implemented on streets with up to 25,000 vehicles per day elsewhere in the country, such as Seattle.

Won't this cause traffic delays and diversion to side streets?

San Francisco has experience with successful road diets on streets with similar volumes to California without significant traffic diversion, including Arguello Boulevard. By providing a center turn lane, which keeps turning vehicles from stopping other traffic, the roadway can function with close to the same capacity as it does today. California carries about 16,000 vehicles per day, while road diets have been implemented on streets with up to 25,000 vehicles per day elsewhere in the country.

Frequently Asked Questions

California Street Safety Project

The SFMTA is measuring traffic volumes on California, Clement and Lake streets to identify any traffic diversion as a result of the project. Adjustments can be made to address any issues that are identified during the 2-year evaluation phase of the project after it is implemented.

As a response to the feedback we heard from the community regarding concern about potential traffic diversion to other local streets, we'll be gathering additional data on California Street to ensure this is the right treatment for the road.

It's also important to note that all Quick-build projects are built with elements that can be removed or adjusted if needed. The SFMTA will be evaluating the impacts of the project over a 24-month period, to ensure that safety goals are being met and that vehicle traffic changes do not slow down Muni service. Adjustments can be made to address any issues that are identified during the 2-year evaluation phase of the project after it is implemented.

Don’t wider lanes cause more safety problems?

In this case, reducing the number of lanes will address the risk of a multiple-threat collision, which happens when one vehicle stops for a pedestrian but the vehicle in the lane next to it doesn’t. Reducing the number of lanes can also reduce speeding.

Very narrow lanes can be appropriate on low-volume residential streets, but with the volume of large vehicles and transit vehicles that use California Street, they can lead to sideswipe collisions. In this case, we expect that wider lanes - but fewer of them - will improve safety on the street. A similar road diet on 25* Avenue, with a similar change in lane widths, reduced collisions by almost 20%. On Fulton Street between Central and Masonic, a similar road diet reduced injury collisions by 43%.

Can this project be reversed if it’s not working?

Isn't the answer more STOP signs?

Collisions in the project area have occurred at all types of intersections and have primarily been associated with issues other than failure to yield at intersections that don’t have all-way STOP signs.

Why are you adding a center turn lane instead of bike lanes?

California Street is an important corridor for transit, with buses arriving every 3-4 minutes in the peak period. The center turn lane will allow buses to keep moving smoothly by keeping left turning vehicles out of the way. This will also help to reduce delay to general traffic, as left turns can add significant delay. The center turn lane also provides an option for vehicles to pass other vehicles that are double-parked in the corridor without having to enter the oncoming lane of traffic.

Frequently Asked Questions

California Street Safety Project

Bicyclists are allowed to use any street, but Lake Street provides an alternative route with bike lanes one block north of California Street. Lake Street has about half the traffic volume of California Street, which may make it a more comfortable street to ride on.

Will you be making similar improvements to other parts of California Street?

Additional transit and pedestrian safety improvements will be made in the future as part of the 1 California Muni Forward project. This may include upgrades such as sidewalk widening at intersections to enhance pedestrian safety. We hope to start outreach in the next two years on these improvements.

Other safety improvements could be identified in the future in areas of California Street that are on the Vision Zero high- injury network. Additional traffic calming improvements will be made on California Street through the Central Richmond Safety Project. Please visit the project webpage for more information at SFMTA.com/CentralRichmondSafety

How will you be evaluating the project?

We will be evaluating the following metrics: e = Traffic volumes and diversion e = Traffic speeds e Drivers yielding e = Transit travel times

How will this affect transit?

The project is designed to reduce collisions involving transit vehicles, which will improve safety and prevent delays when vehicles are taken out of service after a collision. We do not anticipate a significant change in travel time for transit, but we will also be measuring the impacts as part of the project evaluation. This project will allow express buses to more easily pass local buses stopped at bus stops, so there may be some improvement in travel time as a result of this change.

When will this project be implemented?

Some pedestrian safety elements will be implemented by the end of 2019. The road diet portion of the project would be implemented in spring 2020.

What will the construction impacts be? The road diet will be installed by SFMTA paint shops. A conservative estimate to finish the project is 1-2 months will crews

working 1-2 blocks at a time. Each block would see a day or two of work at a time of crews grinding out existing lane lines and then painting new lane lines. The implementation time assumes delays due to weather or crew availability.