research >>geocoding crash data

Geocoding the data gathered by the Statewide Integrated Traffic Records System (SWITRS), the primary source of state-level crash data for California agencies, would significantly enhance the data's usefulness in targeting traffic safety programs and evaluating safety measures' effectiveness. But there are many barriers to achieving this objective, including lack of standardized hardware and the high cost of institutional changes in how data is recorded and transmitted and of ensuring the data is accurate.

completed

From 2004-2006, the TSC provided technical assistance to the CHP in using GIS data to locate clusters with high rates of alcohol-involved crashes.

TSC Resources

"Zeroing in on Drinking-Driving, Mapping, Data Analysis, and Surveys Help Highlight Problems and Reduce Risk," TSC Online Newsletter, Winter 05-06.

in progress

"A comprehensive approach to geocoding collisions from the California Statewide Integrated Traffic Records System (download PDF of PowerPoint™ presentation—600K)," presented by John Bigham, MPH, GSR at the UC Berkeley Traffic Safety Center. May 2008.

One of the geocoding adjustments that needs to be made is differentiating between the different branches of bi-directional streets, like Shattuck Ave. in north Berkeley (left). Click on image for larger view.

Using multiple software applications and custom code, TSC has developed a methodology and work flow that takes full advantage of all location information available for collisions in SWITRS. The end result allows more collisions to be geocoded in a more precise manner than previous efforts.

 

 

An aerial photo of the same stretch of Shattuck Ave. Click on image for larger view.

 

 

 

 

 

 

Transition to Geocoded Crash Data

The TSC is working with local and state agencies, notably the California Highway Patrol (CHP), to identify ways to make a timely transition to geocoded crash data.

TSC Resources

"State-Level Geocoding of SWITRS Data," Proposal Outline, by David R. Ragland.