Paper Details

TRB 89th Annual Meeting (January 10-14, 2010)

Event Number:	635
Event Title:	Geospatial Analysis in Asset Management, Safety, and Routing
Event Date:	Jan 13 2010 9:30AM- 12:00PM
Event Location:	Hilton, International Center
Event Description:
Event Agenda:

Geocoding Police Collision Report Data from California: Comprehensive Approach (10-2618)

Background Collision geocoding is the process of assigning geographic descriptors, usually latitude and longitude coordinates, to a traffic collision record. On California police reports, relative collision location is recorded using a highway postmile marker or a street intersection. The objective of this study was to create a geocoded database of all police-reported, fatal and severe injury collisions in the California Statewide Integrated Traffic Records System (SWITRS) for years 1997-2006. Results The geocoding was completed with a multi-step process. First, pre-processing was performed using a scripting language to clean and standardize street name information. A state highway network with postmile values was then created using a custom tool written in Visual Basic for Applications in ArcGIS software. Custom VBA functionality was also used to incorporate the offset direction and distance. Intersection and address geocoding was performed using ArcGIS, StreetMapPro 2003 digital street network, and Google Earth Pro. A total of 142,007 fatal and severe injury collisions were identified in SWITRS. The geocoding match rate was 99.8% for postmile-coded collisions and 86% for intersection-coded collisions. The overall match rate was 91%. Discussion The availability of geocoded collision data will be beneficial to clinicians, researchers, policymakers, and practitioners in the fields of traffic safety and public health. Potential uses of the data include studies of collision clustering on the highway system, examinations of the associations between collision occurrence and a variety of geographic variables on environmental and social characteristics, including housing and personal demographics, alcohol outlets, schools, and parks.

Authors
     Bigham, John M., University of California, Berkeley
     Rice, Thomas M., University of California, Berkeley
     Pande, Swati , Safe Transportation Research & Education Center, University of California, Berkeley
     Lee, Junhak , University of California, Berkeley
     Park, Shin Hyoung , Korea Expressway Corporation
     Gutierrez, Nicolas , University of California, Berkeley
     Ragland, David R., University of California, Berkeley