Victoria Police say the practice of targeting "low-level speeding" on the state's roads is saving lives.

Police said 60 per cent of speed-related deaths last year resulted from low-range speeding incidents.

During that period nearly 40,000 motorists were fined for driving less than 10 kilometres an hour over the limit.

Assistant Police Commissioner Robert Hill said anyone who criticised police operations targeting low-range speeding as revenue-raising did not understand the realities of traffic accidents.

"Those critics need to sit in the back seat of my police vehicle when I attend one of these horrific incidents where people have lost their life," Assistant Commissioner Hill said.

According to police statistics, about one third of the 249 road deaths on Victoria's roads last year were speed-related.

"Of that 30 per cent, 60 per cent relates to low-level speeding," Assistant Commissioner Hill said.

He said penalising those motorists was making a difference to the road toll.

"Well, the evidence is quite clear in terms of driver behaviour, the evidence is quite clear in terms of what we're seeing across the road system, where there is a reduction in the average speeds travelled," he said.