An Automated Process of Identifying High-Risk Roads for Speed Management Intervention

Abstract

Infrastructure Risk Rating (IRR) is a significant input to the speed management framework, set to be introduced as part of NZ Transport Agency's Speed Management Guide. It is a road assessment methodology designed to assess risk based on infrastructure elements and interactions with surrounding land use, independent of crash history. The road safety risk is assessed by coding each road and roadside feature; such as land use, road stereotype and alignment; that feeds into the IRR model so that a risk rating can be determined. The methodology was originally developed as a manual coding exercise using street view imagery. However, this approach is neither economic nor time efficient when applied across a large network as is the requirement of the speed management framework.