Parts of the Auckland Harbour Bridge could be out of action for several weeks after it was damaged on Friday when strong wind gusts played havoc with two trucks.
There is still heavy traffic congestion affecting Auckland's motorways as structural engineers continue to assess damage to the Harbour Bridge caused by two truck crashes on Friday.
In a statement released yesterday afternoon, the NZTA warned Auckland motorists that there will be "significant reduction in the capacity of the bridge for several days and potentially up to several weeks".
Just after 11am yesterday, a southbound shipping container truck was blown sideways by wind gusts of up to 127km/h and hit the bridge's superstructure.
While the truck righted itself and carried on, a steel upright was sheared off, said Waka Kotahi senior journey manager Neil Walker.
"Our first assessment of the structural damage is that a permanent fix will be a long term process and the four lanes across the centre span of the bridge will remain closed to traffic for at least several days and potentially weeks.
"Congestion on the road network is inevitable as we assess the damage and the necessary repairs. Waka Kotahi recommends customers consider working from home and if they do need to travel into and out of the CBD they consider alternative travel options, such as taking public transport, including the Northern Busway which is not affected."
Heavy traffic flows northbound from Auckland city after a crash over the Harbour Bridge caused lane closures. Photo: RNZ / Katie Fitzgerald
Motorists have been urged to travel along the Western Ring Route (SH20, SH16 and SH18) around the harbour, if possible.
"We are looking at whether we can make a temporary repair, but we won't know if it's possible until we investigate further over the weekend. While part of the bridge structure has been damaged, we have no concerns about its overall integrity and safety."
More than 170,000 vehicles cross the Auckland Harbour Bridge on weekdays. With the four centre span lanes closed, there will be just two lanes in each direction.
Walker said the north and southbound clip on lanes are safe to use as they had their own supporting structure.
"Waka Kotahi understands this will cause inconvenience and disruption of and thanks motorists for their patience. We're working to ensure the bridge can be back in operation as quickly."
Traffic on Auckland Harbour Bridge after trucks crash. Photo: RNZ / Nick Monro
In a second crash caused by the wind gusts, another truck rolled, blocking traffic in both directions when it was blown across two lanes and became stuck on a lane barrier.
Both directions of traffic in the middle of the bridge were affected by the crash.
A police spokesperson said no one was injured in the crashes and wind was a likely cause.
The truck rolled on its side, blocking two lanes. Photo: NZTA
127km/h wind gusts on bridge 'a very rare occurrence'
The truck that rolled was hit by a once in a decade freak gust of wind, MetService says.
Communications meteorologist Lewis Ferris said the wind was gusting at just over 60km/h when it suddenly doubled in strength to 120km/h for a matter of minutes.
"They doubled in strength as that front passed over across the Harbour Bridge but then about five minutes after that the wind dropped right off as it turned around to the south-west," he said.
"It's a very rare occurrence. In the last 10 years the Harbour Bridge has only recorded comparable speeds just once."
Ferris said the worst of the wild weather is over with no strong winds expected over the weekend.