Transferability of Community-Based Collision Prediction Models for Use in Road Safety Planning Applications

Abstract

Collision prediction models (CPMs) are statistically developed mathematical models that relate the occurrence of traffic collisions to various traits or explanatory variables of locations and zones. This paper describes the use of several recently developed community-based, macro-level CPMs and model-use guidelines in a CPM transferability case study for spatial and temporal transferability. The objective was to test the model-use guidelines in an application that involved transferring CPMs developed using 1996 data for the Greater Vancouver Regional District (GVRD) for use in the Central Okanagan Regional District (CORD) using 2003 data. The GVRD and CORD are regions located 400 km apart in the Province of British Columbia, Canada. The case study was carried out in two parts. First, CPMs were developed using 2003 data for the City of Kelowna following recommended community-based, macrolevel collision prediction model development guidelines. Second, existing CPMs were transferred from the GVRD to the CORD, using the recommended transferability guidelines. An analysis of the results revealed that macrolevel CPM transferability was possible and no more complicated than microlevel CPM transferability. To facilitate the development of reliable community-based macrolevel collision prediction models, it is recommended that CPMs be transferred rather than developed whenever and wherever communities lack sufficient data of adequate quality.