Enhanced identification of high-risk intersections

The NZ Transport Agency’s High-Risk Intersections Guide introduces new assessment techniques for identifying the risk of someone dying or being seriously injured in the future. The assessment techniques have been developed using industry knowledge of the inter-relationships between speed environment, intersection form and control type and crash movements to estimate risk. The departure from a wholly reactive approach to road safety allows high-risk intersections to be identified before people are killed or seriously injured.
Having assisting the NZ Transport Agency with the development of the risk assessment techniques the next challenge confronted by Abley Transportation Consultants was to develop a mechanism for calculating the risk profile of all intersections in a town, city or region in a cost-effective and time-efficient compared to the manual equivalent. This paper describes the GIS-based process that was developed to ensure each intersection is assessed in a standardised and equitable manner. Aside from enabling Road Controlling Authorities to make informed decisions about prioritising countermeasure improvements, the process has helped unlock the true value of the transport related data that organisations often put great effort and expense into collecting. The paper goes on to demonstrate the robustness of the risk estimation process by comparing recent fatal and serious crashes at intersections against prior risk estimates of the occurrence of those high-severity crashes.
This paper will be of interest to everyone involved with the targeted identification, prioritisation and funding of road safety improvements, and those seeking to unlock the true value of transport datasets.