Abstract

A GIS Based Procedure to Measure Crash Type Over-representation
Track: Transportation
Authors: Darryl dePencier, Li Jin

The Highway Safety Manual (HSM) attempts to provide a standardized set of analysis methods to move us beyond the traditional reactive approach to traffic safety studies where we only look for locations with high crash frequencies. It offers tools to help prioritize safety improvements that are likely to reduce crash rates based on crash patterns rather than the total number of crashes that occur. Many of the methods have been developed with the assumption that only limited data will be available. There is still a lack of software to support many HSM methods, but GIS can help. This presentation discusses the "Crash Type Over-representation" method which examines a transportation network for instances where locations have a greater proportion of one particular kind of crash, for example rear-end crashes, than would be expected for similar locations within the study area. It does not require traffic volumes to be effective.