209246 A web-based tool to query and map police collision report data

Monday, November 9, 2009

Thomas M. Rice, MPH, PhD , Department of Environmental Health Services, University of California Berkeley, Berkeley, CA
John M. Bigham, MPH , Traffic Safety Center, University of California Berkeley, Berkeley, CA
Jiyeon Lee, MS , Traffic Safety Center, University of California Berkeley, Berkeley, CA
Shin-Hyoung Park, MS , Traffic Safety Center, University of California Berkeley, Berkeley, CA

Many injury prevention researchers and practitioners in California use electronic police collision report data obtained from the California Statewide Integrated Traffic Records System (SWITRS). Currently, to access the data, an agency must request that a California Highway Patrol staff member run a database query and deliver the data set or data tables. The objective of this project was to develop a web-based tool to allow querying and mapping of fatal or severe injury collisions in SWITRS.


SWITRS data were obtained and geocoded in an earlier project. The data were stored in a MySQL database. A query system was designed using Apache web server, PHP programming language, JavaScript, and Google Maps.


A point-and-click interface allows users to select collision records by year, county, city, day and time, collision severity, alcohol use, and numerous other collision factors. Alternatively, the query can be defined by uploading a file of SWITRS Case IDs. Selected data can be downloaded in .csv or .xls format, mapped using Google Maps, or exported as a Google Earth file.


A user-friendly, web interface was created to facilitate the use of SWITRS data with geographic coordinates. The tool may lower barriers to California traffic collision data and increase the use of empirical data in traffic injury prevention activities.

Learning Objectives:
1. Describe the objectives and potential uses of the tool 2. Discuss the primary querying and mapping features of the tool 3. Understand how to use the tool to query, download, and map collision data

Keywords: Geographic Information Systems, Motor Vehicles

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: Have worked as a GIS professional for 8 years.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.