The operator of Melbourne's Citylink tollway has defended the road's safety record after an accident left a truck hanging off an overpass on Friday morning.
The truck's driver, Yosef Jaffary, 39, remains in a critical condition in the Royal Melbourne Hospital after falling about 15 metres from the vehicle's cabin onto a street below.
Motoring groups say CityLink's design needs to be investigated and its speed limit should be reviewed.
But in a statement, the tollway's owner, Transurban, said the incident was "extraordinary" and the road has one of the best safety records in the state.
Neil Chambers from the Victorian Transport Association said authorities should consider lowering the road's speed limit.
"Particularly if you can change it in a variable way during peak [traffic]," he said.
"[It] actually does reduce accident risk."
Police say the large truck was travelling southbound in the right-hand lane on the CityLink when a car tried to merge in front of it.
The truck is then thought to have jack-knifed while trying to take evasive action and then bounced across the freeway before coming to rest on top of one of the side barriers.
The trailers dangled precariously over the side of the bridge and Mr Jaffary fell from the upside down cabin.
Mr Jaffary's family has released a statement thanking the public for their support and asking for privacy.
Transurban said it will continue to work with the Victorian Government to improve the road network.