Traffic Calming Program

The SFMTA's Traffic Calming Program seeks to make San Francisco safer and more comfortable for residents, pedestrians, children, bicyclists, and drivers by designing our streets to encourage slower speeds. Typical traffic calming measures include speed humpsmedian islandstraffic circles, changes to the lane width, or lane shifting.  These measures have been shown to reduce speeding and increase safety.

Why are speeds important?

A car’s speed has influence on not only the probability of a collision, but on how deadly that collision could be. For example, a pedestrian struck by a car moving at 30 mph is six times more likely to die than a pedestrian being struck by a car moving at 20 mph. For this reason, reducing speeds is the primary focus of the SFMTA’s Traffic Calming Program.

Traffic Calming in San Francisco

San Francisco takes a “three-track” approach to traffic calming to ensure that the solutions are appropriate given the characteristics and uses of different streets. These “tracks” include local residential streets, arterials, and streets with schools on them.  Treatments that make sense on a quiet residential street may not work on a high-volume arterial, and vice versa.  These three tracks – Local, Arterial, and Schools – are further broken down as follows:

Application-Based Residential Traffic Calming (Local Track)
Residents can apply for speed humps to be added to their streets if they feel there is a speeding concern. Applications are evaluated based on criteria such as speeds, collisions, and volumes. When there is significant speeding but speed humps cannot be installed, measures like median islands, chicanes, or traffic circles can be considered.

Traffic Calming and Pedestrian Safety at Schools (Schools Track)
In the Application-Based Traffic Calming Program, applications from streets where there are schools are given increased priority.  In addition, our Safe Routes to Schools program improves streets near schools throughout the city, using a pedestrian safety toolbox that includes traffic calming measures.

Traffic Calming on Arterials and Commercial Corridors (Arterials Track)
Speed reduction is one of the many ways that the SFMTA can make busy thoroughfares safer for people walking, biking, and driving.  Currently, the SFMTA’s efforts on arterials and commercial corridors involve a variety of streetscape improvements in addition to speed reduction.

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Traffic Calming Toolbox

Typical traffic calming measures include speed humps, traffic circles, median islands, changes to the lane width, or lane shifting.  These measures have been shown to reduce speeding and increase safety.

Speed Humps (and Speed Cushions)

A speed hump is a raised area in the roadway designed to slow cars without creating the noise, vibration or safety issues associated with older speed bumps, like those found in parking lots. A speed cushion is a speed hump with slots cut out so that buses can drive through with minimal vertical deflection. This design is safer for standing customers who would would be jolted by a speed hump. Speed cushions are generally only installed on Muni routes in the City.

Medians and Traffic Islands
Raised medians narrow the feeling of travel lanes, which encourages drivers to go more slowly. Traffic islands are used at intersections, where they provide a pedestrian refuge. Traffic islands an medians can also provide an opportunity for landscaping and visual enhancements to a neighborhood. 

Lane Shifting / Chicanes
A combination of striping changes, islands, curb extensions or parking changes can be used to narrow lanes and create curvature in an otherwise straight stretch of roadway. This combination is called a "Chicane" and slows cars down by requiring more careful navigation of the roadway.

Traffic Circles
A traffic circle is a raised island in the middle of an intersection. It helps control the right-of-way through the intersection and forces drivers to slow down. The circle also provides an opportunity to increase landscaping in the neighborhood.

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