Truck driver plummets 20m from bridge

A man has fallen about 20 metres from his truck on to a road beneath Melbourne's Bolte Bridge in a dramatic accident that has caused peak hour traffic chaos.

The man's truck is dangling precariously from the bridge, part of the busy CityLink, and the road has been closed.

Police said the truck collided with a car on the bridge shortly after 6.30am (AEST).

The driver of the truck was ejected from the cabin and fell on to Mark Street, which runs below the Bolte Bridge.

Ambulance Victoria said the man was taken to Royal Melbourne Hospital in a serious condition.

The female car driver was taken to hospital in a stable condition.

Police are advising motorists to avoid the area and heavy haulage equipment will be brought in to remove the truck.