100km/h too fast on undivided road: expert

A road crash investigator in Australia has called for the abolition of 100km/h limits on undivided roads. Photo / John Borren

A road crash investigator in Australia has called for the abolition of 100km/h limits on undivided roads.

Peter Bellion, the collision reconstruction team leader for the Victorian state police, said cars travelling at 100km/h in opposite directions with less than a car's width between them were a recipe for disaster.

He said advances in vehicle design meant the chances of surviving an 80km/h impact had improved greatly, but the forces of an impact at faster speeds meant survival was unlikely because of "complete structural disintegration".

"Even with the most sophisticated car, we can't survive that [above 80km/h], and yet we still have undivided roads with 100km/h limits and a white line separating you from the oncoming traffic," he told a Society of Automotive Engineers forum in Melbourne.

Bellion was reported by the website GoAuto as saying there should be more margin for error.

"Why do we still have 100km/h limits when someone makes the slightest mistake, somebody is going to pay for it with their lives?"

He said multiple fatalities on such roads were far too common and suggested that reducing the speed limit to 80km/h, or building more divided roads, would give drivers a far better chance of survival.

Bellion's call comes as New Zealand counts the cost of the worst Easter holiday road toll in 17 years.

In the seven days until Thursday, 18 people had been killed in 12 road accidents, most of them on undivided roads.

Speed and alcohol were suspected as factors in five of the crashes.

Bellion also highlighted the role of new technology such as electronic stability control (ESC) in reducing road fatalities and injuries.

He said about 30 per cent of crashes attended by police in Victoria would involve an incident that would trigger an ESC system.

The technology was a life-saver, but he said drivers should be trained to make the most of it. "They [ESC systems] are making a difference, but it also comes down to driver training and how to steer away from hazards, not just letting it go completely."

Airbags were also saving lives, he said. "That has definitely reduced road trauma in this state.

"I have found that, before frontal airbags, the delta of the speed change during a fatal crash was typically about 60km/h. So if someone hit at 60km/h that was it. But now that is going up to about 80km/h."

He said side airbags appeared to be helping, with occupants more likely to survive a side impact at 40km/h with side airbags while a 30km/h crash would likely kill occupants of a car without side airbags.