While recent California legislative reforms grant jurisdictions greater flexibility to lower speed limits, evidence suggests that reductions in posted speed limits alone are insufficient to meaningfully reduce crash severity. This research brief examines how speed limit reductions, when paired with infrastructure design, enforcement strategies, and contextual land-use planning, can more effectively lower FSI outcomes. Aligned with the Safe System Approach, the countermeasure layers of roadway geometry, lighting, bicycle-specific infrastructure, and enforcement shape driver behavior and...
Bicycling provides youth with mobility, independence, and opportunities for physical activity, but head injuries remain a leading risk of biking-related crashes. Helmets are among the most effective tools for preventing serious injury, yet rates of consistent use among children and adolescents remain low and unevenly distributed across demographic groups. This paper reviews evidence on the social, cultural, and structural factors shaping helmet use and examines the role of school-based programs in promoting safer biking practices. Findings indicate that free and subsidized helmet...
Road fatalities are rare outcomes of events that occur in a small time-space region. Although the exact chain of events for each fatality is unique, there are inherent similarities between road fatalities. The science of road safety is dedicated to identifying such similarities, mainly using statistical analysis tools. Researchers typically analyze patterns that emerge over space, such as hot-spot studies, or patterns that emerge over time, such as before-after studies. Traffic research enumerates 84 parameters that characterize a road fatality. A vast number of papers have tried to...
Workplace motor vehicle incidents at Caltrans are a significant cause of injuries, employee lost time, and property damage. Because backing crashes are major contributors to motor vehicle incidents, identifying and promoting methods of reducing backing accidents is a top priority. According to internal Caltrans’ data, 92.3% of workplace backing crashes were preventable by the driver. Backing crashes are the single largest category of preventable crashes, representing 30% of preventable crashes in the Caltrans fleet. From 1998 through 2007, preventable backing crashes cost Caltrans at least...
