A new road safety campaign from the Motor Accident Commission (MAC) is warning South Australian drivers of the dangers of low-level speeding.

The commission says drivers tend to acknowledge the risk of speeding, but think it doesn’t apply to them.

MAC Chief Executive Officer Jerome Maguire said low-level speeding is a dangerous issue because of the large proportion of drivers who speed by a small margin.

"Creeping over the speed limit has a contagious effect on drivers causing them to adopt higher speeds,” he said.

"So even though drivers may not be involved in a crash, they’re still contributing to the trauma on our

Roads.

"Drivers tend to underestimate crash and injury risk and over-estimate their driving ability, so while they acknowledge the risk of speeding, they believe it doesn’t apply to them.

"The message is simple, if drivers do the right thing and drive within the speed limit, lives will be saved and serious injuries will be prevented."

Acting Road Safety minister Tom Kenyon said about 23 per cent of motorists still speed, and almost four in every five speeding fines issued are for low-level offences.

"Infringement data from SAPOL shows that 38 per cent of expiation notices issued in 2011 were for speeding by less than 10km/h over the limit, while about 79 per cent were for speeding by less than 15km/h over the limit," Mr Kenyon said.

"Driving 10km/h over the speed limit in a 60km/h zone virtually quadruples the risk of involvement in a casualty crash and has similar risks to driving with a blood alcohol concentration (BAC) of around 0.10 – twice the legal limit."