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 humps, median islands, traffic circles, changes to the lane width, or lane shifting. These measures have been shown to reduce speeding and increase safety.
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.
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)
Traffic Calming and Pedestrian Safety at Schools (Schools Track)
Traffic Calming on Arterials and Commercial Corridors (Arterials Track)
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
Lane Shifting / Chicanes