Road geometry study reveals new safety strategies

Austroads’ latest published research looks at ways to reduce the fatality rates on Australia’s rural roads

Road geometry study reveals new safety strategies
Austroads says road conditions have a role in around 30 per cent of all rural crashes in Australia


Road narrowing, creative lane markings, and roundabouts could become more widespread on rural roads in Australia, if analysis in Austroads’ latest research is followed.

Its Road Geometry Study for Improved Rural Safety publication draws on existing research literature and its own crash data to identify road design elements that contribute to both the incidence of rural crashes and their severity.

It analyses a range of strategies used by international road authorities to see if there would be a potential impact on Australian roads.

"In-depth crash studies have also shown that the road is a causation factor in about 30 per cent of all crashes," the report’s summary notes.

"It is [also] known to be a factor in the severity outcome of 100 per cent of crashes."

The recommendations cover the use of sealed shoulders, selection of barriers and clear zones, and methods to control speeds in high-risk areas, among other strategies.

The publication also offers greater guidance on the design of low-speed roundabouts in rural areas.

Painted median strips, which create a wider space between opposite flows of traffic on the same road, have been found to reduce crash risks on roads with high volumes or traffic and/or frequent curves.

That’s not the only way crash risks can be reduced through the paintbrush, the report finds.

It says there are have also been positive results from the use of optical speed bars – which give drivers an increased perception of their speed and encourage them to slow down – and lane markings that narrow in the approach to an intersection.

"A treatment to reduce the approach speeds is the placement of a painted centre median, to narrow the lanes," the report says.

"This is supplemented by rumble strips within this median and along the outside of the edge lines of the pavement."

Lane width can be reduced from 3.66m to 2.75m, it says.

The report also outlines hope for a system of "self-explaining roads", in which roads are divided into only a small number of categories based on their safety characteristics.

Each would have its own speed limit that would become almost instinctual for drivers.

"Having a limited number of distinct road classes and making these obvious to the driver by having markings, signs, and road or roadside elements specific to the type of road, is essential to enable road users recognise the class of road they are travelling on and to be aware of the speed limit on that road," the report finds.

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