Trams are crashing into other vehicles more than twice a day on average, a nagging problem that has been blamed on motorists disobeying the road rules.

Tram drivers are said to be "in a constant state of anxiety" about the risk of a crash, poised to make an impossible choice between slamming on the brakes when a car cuts into their path and risking a passenger fall or crashing the tram.

The number of serious injuries on trams has risen this year, driven by a sharp increase in passenger slips, trips and falls.

New figures published by Victoria's transport safety watchdog reveal Melbourne is on track to record the greatest number of passenger falls, serious injuries, and tram-vehicle collisions in at least five years.