This 2016 AusRAP release is a risk mapping crash data from the five-year period from 2010 to 2014. Eligibility for assessment typically requires that a road have a speed limit of 90km/h or more, though some lower speed limit sections are included where they form an integral part of the otherwise higher speed route. Where gaps appear between highway sections on the map, this is typically due to the highway passing through an area without the required speed limit of 90km/h or above. In New South Wales, for example, the portion of the Great Western / Mitchell Highway passing through the Bathurst town centre has not been rated for this reason.
The crash and traffic volume data used in risk maps are obtained from the road authority in each state and territory, and the period 2010-2014 is the most recent for which every state and territory has crash data available. The way an injury is categorised at the crash scene can vary by jurisdiction.
The risk maps presented on this website is based on casualty crashes. A casualty crash is defined as any road crash in which at least one person is killed or injured.
There are two ways to assess the risk of a given section of road based on its number of casualty crashes.
Collective risk measures the density, or total number, of casualty crashes over a given length of road. Collective risk is calculated by dividing the number of casualty crashes per annum by the length of the highway.
Individual risk measures the casualty crash rates per vehicle kilometre travelled based on traffic volume, and so effectively represents the risk faced by an individual driver. Individual risk is calculated by dividing the frequency of crashes per annum by the distance travelled on each section per annum.
Both the collective risk and the individual risk reveal important aspects of the safety of a road section. Previous editions of AusRAP Risk Mapping have the two risk types presented on separate maps. In the interest of producing an easily comprehensible risk assessment, in this report the two risk types have been combined with equal weighting to produce a single risk score per road section (the combined risk score).
The maps on this website are colour-coded according to the combined risk ratings. They provide clear targets for infrastructure upgrades: governments should focus on roads coloured in red and black as a priority.
The cut-off points between colours are determined by ranking sections from worst to least risk across Australia, calculating the total length of road assessed and then dividing this result into five colour bandings, each representing as close as possible to 20 per cent of the network assessed.