Accessible and Practical Geocoding Method for Traffic Collision Record Mapping

Abstract

Numerous studies of geocoding systems have been used to assign geographical coordinates to incident reports identified simply with textual address references. These studies have typically focused on the level of accuracy achieved by various geocoding systems and found that acceptable results can be achieved. Depending on the quality of the input data, a match rate between 70% and 83% can be expected, with varying levels of accuracy. However, few studies have looked at the potential of freely available online geocoding services to spatially locate traffic crash records. It is proposed that although limitations currently exist, services such as the Google Maps API provide sufficient functionality and adequate accuracy for use with a wide variety of geocoding applications. A case study used traffic crash records from a municipality in the province of Quebec, Canada, with the goal of quantifying the geo coding results. It was found that although a competitive match rate was obtained, manual revision was required to ensure that the results returned by the geocoder referred to the same intersection that existed in the input address field.