Thousands of Victorian motorcyclists are escaping speeding fines each year because their bikes cannot be identified from the front, a report by the commissioner for road safety cameras has found.

Gordon Lewis again called for mandatory frontal ID on motorbikes and scooters after the state government failed to adopt the recommendation of last year's annual report.

Mr Lewis said almost 20,000 of the 50,000 motorcyclists detected speeding between mid-2009 and mid-2012 were not fined because of a lack of frontal ID.

The number of motorcyclists avoiding penalty in this way increased from 33 per cent to 42 per cent over the same period.

“That situation cannot be tolerated,” Mr Lewis wrote.