Description
Traffic calming measures include roadway improvements that slow vehicles and enhance safety. There are numerous types of treatments; the more common ones are listed below.
- Speed humps, bumps and tables
- Chicanes, chokers and neckdowns
- Roundabouts and traffic circles
- Lane narrowing and/or landscaping
- Raised intersections
- Bollards
- Rumble strips
- Lane markings and signage
- Road diets
Implementation Details
- Install infrastructure such as speed humps, raised crosswalks, curb extensions, and traffic circles in high-collision zones and school areas.
- Use traffic safety audits and local collision maps to prioritize locations for calming treatments.
- Coordinate with city public works departments to embed traffic calming into pavement management plans and Safe Routes to School programs.
- Consider road diets in downtowns and central business districts, where businesses are more likely to attract foot traffic.
Mitigation Potential
Traffic calming measures reduce vehicle volumes and speeds, reducing the level of stress and perceived danger for bicyclist and pedestrians. The increased safety encourages people to walk, bike, and use transit, reducing VMT.
For more details, see CALTRANS SB743 Program Mitigation Playbook, Road Diets, pg. 35-36 and CAPCOA (2019), Traffic Calming Improvements, pg. 24 for VMT reduction quantification.
Linked Strategies
Equity Considerations
Traffic calming improves safety for pedestrians and cyclists, especially in neighborhoods where residents are more likely to walk or bike. Implementation should prioritize areas with a history of traffic violence or near schools and parks in environmental justice communities. Inclusive engagement is key to ensuring measures align with local mobility patterns.
Funding Sources
Requires funding to construct, plus continued funding for maintenance and operations. Demonstration projects are less expensive and can yield similar results though they are temporary. Active transportation grants and other one-time sources are available (though competitive). Such funding sources include the Regional Active Transportation Program (Metropolitan Transportation Commission ), the Statewide Active Transportation Program (California Transportation Commission), the Local Streets and Roads Program (California Transportation Commission), California Office of Traffic Safety Grants (California Office of Traffic Safety), Safe Streets and Roads for All (United States Department of Transportation), and the Highway Safety Improvement Program (Caltrans).
Implemented in TAM Area
Current TDM Implementation
Traffic calming projects are mostly happening at the jurisdiction level. The City of Novato implements traffic calming measures as part of their Complete Streets initiatives, including bulb-outs, high-visibility signs, and pedestrian warning signals. San Rafael’s recent Spinnaker Point Traffic Calming Pilot Project utilized low-cost, quick-build strategies to reduce traffic speeds, including a traffic circle and median extensions. Other current traffic calming implementation includes Mill Valley’s Slow Streets program, pedestrian safety interventions in Madera Gardens, and Larkspur’s traffic calming policy.
TDM Benefit Locations
While traffic calming can benefit many street types and areas in the county, it is critical in school zones, areas that experience frequent speeding, places with high foot traffic, and unincorporated areas. Marin County’s Local Road Safety Plan identifies a High Collision Network and priority projects that would benefit from this TDM strategy. San Rafael, Novato, and unincorporated Marin County were the were the highest represented jurisdictions in the High Collision Network, indicating a opportunity to benefit from traffic calming interventions.