Victoria Police has gained an unlikely critic in the state's peak motoring body, with the RACV saying officers are wasting their time targeting low-level speeding.

Police are cracking down on drivers travelling 10km/h or less over the speed limit.

Assistant Commissioner Bob Hill Credit:Michael Clayton-Jones

Fines for exceeding the speed limit by less than 10km/h have tripled in five years, from about 11,000 to 38,000 per year.

Road policing command Assistant Commissioner Robert Hill said 30 per cent of road trauma was caused by speeding, with more than half caused by low-level speeding, particularly in 40km/h school zones and shopping precincts.