DEVELOPING A CLEAR ZONE STRATEGY FOR THE DUKES HIGHWAY – A SAFETY PERSPECTIVE
The Dukes Highway forms part of the Adelaide – Melbourne road corridor and forms a link to the State’s South East. A Roadside Hazards Strategy has been identified as a high priority for the corridor.
Substantial federal funds are committed to the Dukes Highway over the next several years with an emphasis on the Safe System approach. The roadside hazard treatment program will be the largest of its kind undertaken in South Australia.
A clear zone of at least 9 metres is recommended by Austroads for high speed roads. Other evidence suggests 85% of safety benefits will be captured within the first 6 metres. Recent research lends support to doubts on the reliability of clear zone theory in the context of a Safe System.
Road reserves contain some of the last remnant native vegetation. To assist in determining the impact of a clear zone at various widths, a vegetation survey was commissioned. There are statutory mechanisms for when vegetation removal is necessary stipulating significant remediation or monetary payment into a dedicated fund. By adopting narrower clear widths in locations with concentrations of high value vegetation, environmental impacts and costs could be minimised while still being able to reduce crash risk with barrier protection.
A process involving discussion papers and consultation has led to a preferred plan. It is likely that this work will influence DTEI clear zone policy into the future.