Work could begin on fixing Auckland's Harbour Bridge from Tuesday night and steel for repairs has arrived from Taranaki.
Waka Kotahi NZ Transport Agency transport services general manager Brett Gliddon said they expected the work would take between two to three nights and the southbound lanes would be closed between 9pm and 5am.
Once the temporary solution was in place they would do "real live tests" before opening two additional lanes later this week.
The detour route while the southbound lanes of the Harbour Bridge were closed overnight was the Western Ring Route.
He said they weren't going to open until it was safe to do so which is why they were undergoing a third independent peer review.
NZTA was throwing a whole lot of resources at repairing the bridge.
The strut was bolted halfway up and were going to unbolt the second bottom piece and attach some new steel.
The challenge with the permanent fit was jacking the bridge and putting some tension into it. They had to make sure that when they put the new strut in it didn't affect the dynamics of the rest of the bridge.
NZTA was being cautions which was why they had closed the centre lanes until the replacement steel was put in.
Gliddon said they were making really good progress on both the temporary and permanent solutions.
NZTA continued to urge people to work from home for the next few days or use public transport as heavy congestion was expected for some time.
He said there had been good deferral of traffic away from the harbour bridge 30 per cent less northbound and 60 per cent southbound - there was still severe congestion across the city.
The first weekday back after two trucks were blown over by strong winds on Friday damaging the bridge's centre span has been met by frustration by motorists as the motorway come to a standstill and in some cases their commute took four times as long.
The hefty delays have prompted NZTA to ask motorists who have only come out of the city's second lockdown three weeks ago to consider staying home or travelling outside peak times.
Only four lanes on the bridge are open and this is expected to remain the case for several weeks so temporary repairs can be made.
This means the bridge will be operating at half its normal capacity pushing traffic out to the Western Ring Route and other state highways and local roads.
NZTA has been advising people if they must travel then to avoid peak times in the morning and evening and allow extra travelling time.
Commuters reported painful trips where they crawled from the North Shore into the city with a Torbay resident saying the journey took him two hours and 35 minutes.
By 7.30am the usual 17-minute trip from Silverdale to Auckland CBD took 1 hour and 7 minutes.
A bus priority system is being introduced before this evening's peak traffic. The priority lane will run on State Highway 1 northbound to the Auckland Harbour Bridge and is aimed at reducing congestion for buses travelling to the North Shore and providing more reliable journeys for customers.
This bus priority system will allow buses to access the SH1 northbound on-ramp at Fanshawe Stt using then new priority lane and bypassing the queuing traffic.
This priority lane onto the motorway will then merge with the general state highway traffic.
While the priority lane is operating, the Curran St northbound on-ramp onto SH1 is closed to all traffic and motorists will be detoured to the Fanshawe St northbound on-ramp.
Auckland Transport has reassured people that there is plenty of capacity on public transport with trains, buses and ferries all able to take more passengers.
Extra buses will also be operating outside peak times.
• Auckland Harbour Bridge traffic: Latest updates as commuters brace for chaos
• Auckland Harbour Bridge: NZTA reveals plan to fix after truck crashes knock out four lanes
• Auckland Harbour Bridge traffic congestion: Latest updates, travel times
• Auckland Harbour Bridge traffic: Congestion on all routes this morning