The New Zealand Transport Agency is urging Aucklanders to plan ahead as strong gusts of wind continue to threaten the Harbour Bridge.
Three lanes heading north and south have reopened on the bridge after being closed due to strong wind gusts earlier on Tuesday.
The lanes were closed for an hour, causing heavy congestion - this has now eased but NZTA is monitoring the situation and warns the bridge could close again.
"Ongoing wind gusts have been a concern since the weekend and [NZTAs] bridge team has been continually measuring wind levels. It is vital we protect this critical piece of infrastructure for the medium and long term," said senior journey manager Neil Walker.
He urges motorcyclists and drivers of high-sided vehicles to avoid using the bridge until high winds in the region abate.
Chaotic weather caused havoc for commuters on Tuesday morning and the temporary closure meant delays of more than an hour for some.
Despite the lanes reopening, Auckland Transport said motorists should expect "significant delays and cancellations to services" as the bridge returns to normal.
"Also, note the bridge may close again on short notice".
In a statement, the NZTA said that closing the bridge was critical to looking "after the safety of drivers and the bridge whilst the structure is still damaged and in a compromised state".
The NZTA acknowledged that closing the bridge would cause "major disruption and inconvenience".
Earlier on Tuesday, the NZTA tweeted that "due to strong wind gusts", there was just a single lane open in each direction. It was initially down to two lanes open heading south and one lane heading north.
"Take extra care & follow posted speed restrictions. Motorcyclists & high-sided vehicles should use #WRR until further notice," the NZTA said at about 6am.
There was already reduced capacity on the bridge after a freak gust of 127km/h caused a truck crash earlier this month, damaging the bridge's structure. A temporary fix was put in place, allowing three lanes to be open in each direction. Motorists are still advised to use the Western Ring Route (WRR) where possible.
New Zealand has been hit by strong winds over the weekend. The NZTA on Monday warned that it was continually measuring wind gusts to assess whether lanes needed to be closed.
"Closures may happen at very short notice. Waka Kotahi acknowledges the lane closures will cause disruption and inconvenience, however safety is our top priority and the lanes closures will be lifted as soon as it is safe to do so," said senior journey manager Neil Walker.
He said lane closures could happen if the gusts reach a threshold of 80km/h or more.
While a temporary fix is in place for the bridge, a permanent repair could still be weeks away. Work is underway to design and manufacture a 22.7m strut that "will be a permanent load-bearing fix for the bridge".
The bridge normally can have up to eight lanes open to traffic.