Connected Vehicle Speed Data for AusRAP Projects

Main Roads Western Australia used Compass operating speed data to establish iRAP star safety ratings

Western Australia set a target to reduce road fatalities and serious injuries by 50–70% by 2030, with the ultimate goal of eliminating these entirely by 2050.

One key initiative is the use of AusRAP Star Ratings, which Main Roads Western Australia aims to apply to roads carrying 80% of the state’s traffic by 2025. These ratings, on a scale from 1 to 5 stars, indicate a road’s safety performance. A 5-star rating reflects the highest level of safety, with risk decreasing significantly as the star rating improves.

AusRAP is based on the globally recognized iRAP Star Ratings, endorsed by the United Nations. These ratings provide an objective way to assess safety by examining the physical characteristics of roads, traffic patterns, and speed data.

This project assessed over 19,000 km of the Western Australian state road network, using advanced technologies to gather and analyze data. Mobile LiDAR and 360-degree imagery were key tools in generating the detailed road attributes required for AiRAP coding. These technologies enabled efficient, large-scale analysis of road features to identify safety risks.

Speed data is a critical element of iRAP assessments. A combination of posted speed limits and operational speeds are used to determine star ratings.

New Connected Vehicle capabilities expand on these existing data sources to collect operational speed data directly from vehicles as they drive around a road network. 

Compass road matched both average and 85th percentile operating speeds for every 100m segment of road, along with near-miss data, for the full 2023 calendar year (excluding public and school holidays).

The project covered over 19,000km of national highways and state roads in Western Australia. It demonstrated the feasibility of large-scale AiRAP safety coding, leveraging a combination of data sources—including real-world driving speeds from connected vehicles. These insights support evidence-based decision-making and are a significant step toward meeting Western Australia’s ambitious road safety targets.