Drivers face the prospect of an 80 kilometre an hour limit on country roads, if one researcher has his way.
The researcher is Craig Kloeden, of the influential Centre for Automotive Safety Research at the University of Adelaide.
He said he would ideally like to see 80km/hr limits on country roads.
The roads could include Augusta and Spencer Highways, Main North Road and dozens of other rural links.
Mr Kloeden’s suggestion is based on evidence that lower speeds result in reduced death and injury tolls.
“Some of the country roads should be classified 80km/hr,” he said.
“In the United States, rural roads typically have limits of 70km/hr to 90km/hr and we have 110km/hr.
“It is probably a big step to take.
“Unsealed roads should not have a limit of more than 80km/hr and undivided roads should ideally have an 80km/hr limit.”
He said that reducing limits from 110km/hr to 100km/hr would increase travel time by 10 per cent, which represented about six minutes longer.
Meanwhile, lowering the limit further from 100km/hr to 80km/hr would save another 20pc in travel time or about 12 minutes.
“You have one quarter the chance of being involved in an ‘injury crash’ at 80km/hr compared with 100km/hr,” he said.
“If you look at the physics of the situation, it makes sense.
“The slower that people are travelling, the less likely they are to be involved in a crash and be injured.”
He said many country roads were narrow and lined by trees – a recipe for disaster.
Mr Kloeden has worked at the centre for more than 30 years.
Some roads in the Adelaide Hills have already become 80kmh zones as a result of recommendations by the centre.
His comments are likely to attract criticism from country road-users.
There has already been an outcry over reduction of limits from 110km/hr to 100km/hr.