Massive West Gate Bridge cracks spark war of words Acting Chief Executive VicRoads Peter Todd says the West Gate Bridge is safe to travel on after two cracks were repaired overnight ONE of cracks that shut the West Gate Bridge yesterday causing traffic chaos was 29m in length, VicRoads has revealed. All inbound lanes opened to traffic at 6am today after urgent repairs overnight. VicRoads Acting Chief Executive Peter Todd said the crack was caused from a separation of two waterproof membranes underneath the asphalt layer. He said one of the cracks was 5m in length, the other was 29m, and they were 40mm deep. He said yesterday that the bridge was "absolutely safe," and that the cracks were "just a surface defect." "Neither in any way affected the structure or the strength of the bridge," he said today. We strongly suspect that the damaged membranes were as a result of last week's extreme heat causing the steel section of the bridge to expand and then contract when the temperatures dropped. This expansion and contraction damaged the membrane that protects the bridge structure from moisture. Three lanes on the city's biggest and busies bridge were closed for more than two hours yesterday as VicRoads moved to reassure frustrated motorists the roadway was still safe for travel. The resulting traffic jams, backing up to Grieve Parade in Altona North, sparked new debate about the bridge's long-term viability and ability to cope with an increasing traffic load. Mr Todd said the steel construction bridge, which infamously collapsed during construction in 1970 killing 35 workers, needed ongoing maintenance. The cracks have opened up a war of words between the Napthine Government and Labor Opposition over ways to relieve pressure on the ageing bridge. In a signal that the future of the West Gate is likely to play a role in November's election Opposition Leader Daniel Andrews said the emergency of cracks showed the urgency of getting trucks off the 35-year-old bridge. In 2011 the State Government was warned by VicRoads that "growth in average vehicle weight and traffic volume ... will continue to exacerbate fatigue crack issues that have been a feature of this bridge since it was first opened."