Human error was to blame after the Princes Freeway at Werribee was closed to incoming traffic for several hours after a number of collisions.
Emergency services had to divert traffic into the Werribee and commuters are being told to allow for extra time with significant delays on the freeway on Wednesday morning.
The VicTraffic website said there had been a truck rollover, while its social media posts highlighted a number of incidents on the road earlier on Wednesday.
Department of Transport and Planning road maintenance executive director Michael Bailey told ABC Radio that steel plate on the freeway became loose.
“First and foremost I want to start by apologising to everyone who was affected by this morning’s incident on the freeway, particularly those who had damage to their vehicles,” he said.
“I understand there has been no physical injury there has been a fright associated with hitting an expansion joint which has been dug out.
“Overnight crews were working to replace and expansion joint at the edge of bridge there is an expansion point. The expansion point had reached its end of life.
“We were working through a routine maintenance project to replace that expansion joint. They’ve cut out the old expansion joint, put a steel plate over that with the intention to come back tonight … Between 3am and 4am that has come loose and hit by a truck and multiple vehicles.”
Mr Bailey said they were waiting on Victoria Police to find out what has damaged each of the car, but said most of the vehicles have hit exposed concrete reinforcement within the expansion joint.
He said work on replacing the joint would be finished overnight.
Mr Bailey said it was contractors who had done the work and they were trying to find out what had happened.
“We believe it was human error.”
Mr Bailey said they believed there was 11 vehicles that were impacted.
