Los Angeles and San Francisco using data to target Vision Zero efforts

By Robbie Webber

As cities commit to Vision Zero, they have started to examine intersections and roadway segments with high crash rates, serious injuries, and fatalities to pedestrians. What they have found is that a small percent of roadways account for a large portion of serious crashes. And crashes disproportionately affect certain populations. Intersections and roadway segments with high pedestrian crash rates are often located in areas with populations that are majority low-income, black, brown, non-English speaking, and neighborhoods with generally poor health outcomes. Older and younger residents were also found to be disproportionately represented in fatalities.

The most recent Vision Zero report from Los Angeles found that 65 percent of severe and fatal traffic collisions involving pedestrians occurred on six percent of the city’s streets. In San Francisco, 77 percent of severe and fatal injuries to people walking occur on only 13 percent of the city’s streets, according to a 2015 report—updated in 2017—that maps high-injury corridors.

Unlike most previous research, San Francisco’s Vision Zero High Injury Network study integrated hospital reports with police data. Because patients undergo a full medical analysis, hospital data are more accurate in revealing the extent of injuries than are police reports. Disturbingly, “half of all severe and fatal injuries occur” in “areas with high concentrations of low-income residents, immigrants, and non-English speaking residents and seniors.” Furthermore, seniors constitute half of pedestrians killed by cars, but only 15 percent of city residents.

Los Angeles has also done a High Injury Network study as part of its Vision Zero effort and the data from Los Angeles tells a similar story of disproportionate impact on certain populations. Traffic crashes are the leading cause of death for children 5-14 years old, and 30 percent of those killed or severely injured while walking or bicycling are under 18 or over 64 years of age. Nearly half of the High Injury Network streets are in communities burdened with the poorest health outcomes and economic conditions according to the city’s Health and Equity Index.

The city has the most dangerous intersection in the state, and the road design and land use near the intersection is typical of many of the most dangerous intersections, with multilane, high-speed roads, many driveways, and generally car-oriented development patterns. The FHWA has found that the danger to pedestrians increases with the number of driveways. Speed was also found to be a top contributing factor in fatalities.

Fortunately, both cities have aggressive plans to address problem areas and conditions. The cities are also using a public health approach, considering behaviors as well as the physical environment. And they also recognize that disparate impacts on already burdened populations must be a top priority. However, without the collection and analysis of injuries and fatalities, not just from police reports, but also hospital records, these targeted interventions would have been difficult.

Robbie Webber is a Senior Associate at SSTI.