2019 CSCE Annual Conference - Laval (Greater Montreal)

2019 CSCE Annual Conference - Laval (Greater Montreal) Conference

Transferring Road Safety Planning Models Across Time: Case Study on City of Kelowna, BC

Mr. Vipul Garg, University of British Columbia
Dr. Gordon Lovegrove, University of British Columbia, Canada (Presenter)

Macro-level collision prediction models (CPMs) have been identified as reliable planning-level decision-support tool to facilitate road safety planning. This paper reports on the results of research updating Kelowna macro-level collision prediction models (CPMs). Two objectives of this research were to: 1) Develop a set of updated community-based macro-level CPMs, and 2) Apply these updated models in macro-reactive road safety applications, i.e., identification, ranking and remediation of hazardous locations. Several models stratified by land use (i.e., urban or rural), independent variable class (i.e., exposure, socio-demographics, network or transportation demand management), and data derivation (i.e., measured or modelled) were updated using the data from 183 traffic analysis zones (TAZs) in Kelowna. Generalized linear modelling (GLM) technique with negative binomial error distribution was used. The updated CPM results were in good agreement with past research that developed the original Kelowna models.  One new and significant result in updating the CPMs, due to the availability of new data, was that decreased total collisions in a zone (i.e. neighbourhood) were associated with increases in the proportion of roundabouts, a result seen previously only in micro-level collision prediction models (i.e. looking at individual intersections). The updated CPMs were then applied to present-day Kelowna neighbourhoods, to identify and rank collision-prone zones (CPZs) using the same methods reported previously by Lovegrove & Sayed (2006). Two CPZs have been diagnosed and potential remedies reported on in this paper. This research demonstrates that updated CPMs are practical tools for community planners and engineers and that roundabouts can significantly improve neighbourhood safety. It also demonstrates how little data is needed to identify, diagnose, and remedy collision-prone zones and neighbourhoods in a proactive manner.  This work was conducted using new software under development in UBC Okanagan’s Sustainable Transport Safety Research Lab.


Lovegrove, G., & Sayed, T. (2006). Using Macrolevel Collision Prediction Models in Road Safety Planning Applications. Transportation Research Record: Journal of the Transportation Research Board, 1950(1950), 73–82. https://doi.org/10.3141/1950-09