A record 30 accidents involving cyclists last year has prompted Williamstown police to launch Operation Keepsafe.

The month-long operation will focus on cyclist safety with officers ensuring riders of all ages are adhering to road rules and wearing helmets.

The road accident statistics reflect an increasing number of cyclists using the roads. Most at risk are men over 30, who accounted for two-thirds of riders involved in collisions last year.

Four of the 30 cyclists involved in reported accidents were not wearing helmets and 10 suffered injuries serious enough to be taken to hospital.

These included a 28-year-old rider critically injured when he crossed the railway line at Williamstown North, ignoring warning signals, and was hit by a northbound train.

Almost half the 30 accidents occurred in Williamstown with Douglas Parade, the roundabout at The Strand, and Ferguson Street identified as black spots.

"When cyclists are involved in accidents there's a far greater likelihood of injuries," Sergeant Peter Radford said.

"For one in three to require hospitalisation is pretty high and if they are taken to hospital that is a serious accident, as far as I'm concerned.

"It's a real issue. Just this morning [last Wednesday], there was a cyclist killed over in Epping.

"We were fortunate last year with the 30 accidents that none of them was fatal, and we certainly don't want that to happen this year.

"A lot of this is about being patient on the road, about motorists and cyclists being aware of each other's presence and being a bit courteous."

Sergeant Radford said cyclists needed to be particularly vigilant as they were physically more vulnerable.

"Cyclists need to create a bit of a safety zone around themselves.

"Just keep a watch-out. Look out for that car door opening, be clear in signalling, and wear a helmet."