Transportation Injury Mapping System (TIMS), Safe Transportation Research and Education Center, University of California, Berkeley. 2017

Transportation Injury Mapping System (TIMS), Safe Transportation Research and Education Center, University of California, Berkeley. 2017

Through nearly 40 years of representing accident victims and families, GJEL has shown that many injuries suffered on the roads are preventable. Our efforts to improve traffic safety extend far beyond the legal process. We sponsor organizations such as the California Bicycle Coalition to advocate for safe and viable transportation alternatives. When we learn about traffic safety risks, we encourage friends and neighbors to stay out of harm’s way.

In the spirit of public service, we are launching a series on the GJEL blog called San Jose by the Numbers, looking at the latest data on traffic incidents in the communities surrounding GJEL’s local San Jose office. The purpose of the series will be to answer some basic questions about traffic safety in Santa Clara County, including San Jose and the outlying suburbs. Is traffic safety in San Jose improving or getting worse? Can we use public data to identify danger zones in our community and dangerous time periods when accidents are most likely to occur?

Why San Jose? It has been the third-most dangerous city in California for traffic safety, according to the latest statewide data reported by the California Highway Patrol. Only Los Angeles and San Diego have logged more injuries.

Where to get traffic safety data

It’s not easy to know where to go for traffic safety data. The City of San Jose Department of Transportation has a traffic safety web page where you can report chronic traffic problems and parking problems or request a traffic safety presentation. Santa Clara County also has a traffic safety web page with information about its collaborative Traffic Safe Communities Network, representing law enforcement, engineers, public health, and community organizations.

The central clearinghouse for local traffic records is found within California Highway Patrol’s Statewide Integrated Traffic Records System (SWITRS). Although the SWITRS database primarily serves law enforcement agencies, anyone with an email account can register to enter the system and generate custom traffic safety reports, as long as they accept the terms of service. The terms say that data is “typically seven months behind,” and the California Highway Patrol (CHP) does not guarantee the quality of information in the database, “although CHP attempts to maintain the highest degree of accuracy.”

CHP does compile SWITRS data into annual reports, but as this blog post is being written, the most recent report available on the CHP website is for 2013.

Several organizations have used SWITRS data to provide a better understanding of traffic safety risks in their communities. Two years ago, the Los Angeles Times used the data to analyze over half a million pedestrian accidents and identify the most dangerous intersections in L.A. County. UC Berkeley’s Safe Transportation Research and Education Center (SafeTREC) also uses SWITRS data to display traffic safety data within Google Maps, as seen at the top of this post. SafeTREC’s Transportation Injury Mapping System includes provisional San Jose collision data through 2015.

What’s next in the series

In the weeks ahead, San Jose by the Numbers will look at a wide variety of data from collision scenes to provide a more nuanced understanding of local traffic safety risks. CHP reports on some data at the state level only, such as injuries during holiday periods. Instead of extracting county-level summaries from raw data, we may provide estimates based on statewide averages. All data sources will be acknowledged clearly in each post.

Upcoming topics include:

  •       Collisions during holiday periods
  •       Latest traffic injury data
  •       Collision factors
  •       Alcohol-involved injuries
  •       Bicycle-involved collisions
  •       Truck-involved collisions
  •       Most dangerous roads