The large crack which appeared on the West Gate Bridge on Monday afternoon has been fixed in time for peak-hour morning traffic, VicRoads says.
The speed limit on the bridge has returned to 80km/h after crews worked overnight to mend the 40mm deep crack, believed to have been caused by last week’s heatwave.
The crack, about three metres in length, prompted the closure of two inbound lanes near Williamstown Road from 1pm until about 3.30pm.
Both lanes were reopened in time for the evening peak, with a 60km/h speed limit.
Acting chief executive Peter Todd admitted VicRoads had not yet determined the cause of the crack, which appeared on a section of road that was resurfaced 12 months ago.
“We believe that there’s been a separation of the asphalt from the membrane underneath,” he said.
But VicRoads closed the lanes again on Monday night to inspect and repair the crack.
The authority has reassured motorists that the fissure is “just a cosmetic problem involving the cracking of the bitumen”. The bridge has no structural weaknesses and is perfectly safe, it said.
In August 2007, the state government announced a $240 million plan to identify and eliminate structural weaknesses in the bridge, prompted by the collapse of the Mississippi bridge in the US city of Minneapolis.
Despite these weaknesses, and concerns the bridge was dealing with traffic loads it was not designed for, it was announced in 2008 that the bridge would be widened from four lanes to five in both directions.
In 2011, the new lanes were opened and accompanied by strengthening works in the bridge that took two years to complete.
Each day it carries up to 160,000 vehicles, including 24,000 trucks, according to VicRoads data.