Lowering Speed Limits in Business Activity Districts

Assembly Bill 43, Friedman: Traffic Safety (AB 43) was signed into law in late 2021 by California’s Governor. Under AB 43, local governments may, by ordinance, set a prima facie speed limit of 20 mph or 25 mph on streets contiguous to a “business activity district” (a new designation authorized by AB 43).


AB 43 was signed into law by the Governor


Oakland City Council approved the ordinance


Project Location


On December 6, 2022 the City of Oakland passed an ordinance amending Oakland Municipal Code Chapter 10.20 (Speed Limits) establishing 20 MPH and 25 MPH speed limits in Business Activity Districts (BADs), as defined by AB 43 and summarized in this report. AB 43 strikes a balance between allowing greater local flexibility and ensuring that speed adjustments are completed incrementally[1].

This work is important because traffic safety is a critical issue in Oakland. Every week, two Oaklanders are killed or severely injured in traffic crashes on city streets. These crashes are also highly concentrated – with 60% of severe and fatal crashes occurring on just 6% of Oakland city streets, identified as Oakland’s high injury network (HIN). These crashes disproportionately harm people in Black, Indigenous, and people of color (BIPOC) communities, people with disabilities, seniors, and low-income communities. Safe Oakland Streets (SOS) is a Citywide initiative to prevent severe and fatal crashes, eliminate injury inequities, and carefully assess and mitigate any equity impacts resulting from safety measures.

Speed limit reductions were prioritized because they have been found to be effective on their own at reducing speeding and preventing severe and fatal injuries. In addition, speed limit lowering can be even more effective when coupled with engineering measures to reduce speeds and increase visibility. OakDOT continues to deliver both short- and long-term traffic safety improvements in Business Activity Districts throughout the city. Speed limit lowering in Business Activity Districts is advancing SOS Policy Strategy 3.4: CAO, DOT, and OPD to advocate for State policy for local speed limit reductions to improve safety and save lives.

Implementation and Prioritization

Fifty-seven (57) corridors totaling 26.5 miles in Oakland were identified through a comprehensive, citywide analysis to identify eligible districts.

OakDOT will begin implementing reduced speed limits for 10 Business Activity Districts by Summer 2023[2].

Implementation will prioritize eligible corridors on the High Injury Network and in the Highest Priority Equity Areas, starting at the top of the list available here. OakDOT further aims to implement signage in all identified eligible Business Activity Districts as feasible by the end of 2025.


OakDOT will work to engage Council Offices, Neighborhood Councils, AC Transit, and Safe Oakland Streets partners as speed limits are lowered and new signage is installed.


To support public notification and respond to concerns related to increased traffic citations in communities of color and low-income communities, AB 43 establishes that a local authority may issue only warning citations for violations exceeding the speed limit by 10 MPH or less for the first 30 days that a lower speed limit is in effect as authorized by this section of this bill.


[1] According to state law cities are mandated to conduct a traffic and engineering survey to determine a street’s speed limit via the 85th percentile method. This method is based on the premise that the speed limit should be set at the speed which the majority (85%) of drivers travel under, as measured by an engineering and traffic survey, rather than a speed that is safe for all road users. This method is counter to safely setting speeds that would reduce the risk of severe injury or death in a crash – in fact, it is known to increase speed limits over time. For the most part, the bill doesn’t remove the 85th percentile approach to speed limit setting in California, rather it adds several very specific strategies to help enhance safety while continuing the 85th percentile approach.

[2] Legislative Criteria for Business Activity Districts

Per the AB legislation, Business Activity Districts are defined as that portion of a street and the adjoining property contiguous thereto that includes central or neighborhood downtowns, urban villages, or zoning designations that prioritize commercial land uses at the downtown or neighborhood scale.

These streets must have four or fewer traffic lanes.​ And meet at least three of the following four requirements, inclusive: ​

  1. No less than 50 percent of the adjoining property fronting the highway consists of retail or dining commercial uses, including outdoor dining, that open directly onto sidewalks adjacent to the highway. ​
  2. Parking spaces located alongside the highway (including parallel, diagonal, or perpendicular spaces). ​
  3. Traffic signals or stop signs located at least every 600 feet. ​
  4. Marked crosswalks not controlled by a traffic control device.

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