Temporary repairs on the Auckland Harbour Bridge that opened up two extra lanes have had an immediate effect as the heavy traffic jams plaguing the city have eased much quicker tonight.
All motorway routes north, south and west were now flowing freely, according to Google Maps.
The Waka Kotahi NZ Transport Agency also earlier tweeted that traffic was flowing freely towards the North Shore, both over the Harbour Bridge and along the Western Ring Route detour.
Earlier today transport bosses acknowledged Auckland's "horrific" traffic delays after damage caused by a bridge striking a metal support strut on the bridge brought much of the city to a gridlocked standstill last Friday.
The damage led authorities to shut four of the Harbour Bridge's eight motorway lanes.
NZTA teams were able to make a temporary fix overnight by bolting a new strut into place. This temporary fix enabled authorities to open up two more lanes, giving motorists three lanes in each direction over the bridge.
However, the NZTA warned that the bridge remained "vulnerable" despite the repairs.
NZTA general manager transport services Brett Gliddon told reporters today that repair teams were still working on a permanent repair solution.
Heavy vehicles are still being urged to avoid the bridge and to use the Western Ring Route instead.
Gliddon thanked Aucklanders for their patience during the "horrific" delays.
It would still take four to five weeks to permanently repair the bridge as engineers sourced the steel and worked on a design that would then have to be peer-reviewed by other experts.
However, he was very relieved when temporary repairs allowed transport teams to open two more lanes over the bridge this morning.
Traffic jams were "markedly shorter as a result. But commuters were still asked to change their travel patterns by taking public transport or using the western detour route.
"In this temporary configuration, the bridge is still not fully operational, two lanes remain closed, and motorists should still expect queues and delays crossing the bridge at peak times," Gliddon said.
Teams would now monitor the performance of the bridge and its temporary fix every day.
"Because if we have any concern, we will 100 per cent shut it down again," Gliddon said
NZTA did not yet know how much the repairs would cost, saying the overnight repair was all about speed and safety.
A permanent fix was much more complex, Gliddon said.
Teams wanted to make sure that any fix matched well with the bridge and didn't put any extra strain on other parts of the structure.
Then it would need to be double and triple peer reviewed by other experts, Gliddon said.
He said the bridge was still in a "vulnerable" state.
That was why two lanes remained closed and heavy vehicles were recommended to take the Western Ring Route if possible and the speed limit had been reduced to 50km/h.
The permanent fix would take four to five weeks to be installed at which point the bridge would operate as normal again.
The time taken in completing the repairs was all about the calculations and equations needed to make sure the fix worked as expected.
Design consultants Beca would design the permanent repair of the bridge. Their design would then be peer-reviewed by other consultants.
Gliddon said NZTA had not made a final decision on the preferred option for a second harbour crossing. However, it was likely to be a tunnel.
It comes after a freak gust of wind on Friday morning blew a truck into a metal support strut, damaging the bridge and forcing engineers to close four of the eight lanes.
Auckland motorists subsequently endured a painful week of gruelling traffic jams stretching from the south of the city to the north and west.
However, perfect Auckland weather overnight helped work teams temporarily replace the strut with a section of freshly fabricated steel.
Specialist bridge engineers and fabricators assessed the damage, designed the new strut, calculated and planned the repair as well as manufactured the strut itself.
NZTA said: "We had perfect weather conditions on the harbour bridge overnight and so progress was much faster than we had hoped.
"There was very little wind, good temperatures and visibility - which meant the team were able to get the new section installed and carry out the testing all in one night."
Gliddon thanked all members of his team for working flat out to try and get traffic moving again over the bridge.
The fix meant three lanes were being opened to traffic coming from either side of the bridge from early this morning.
NZTA said although that was hugely positive for the public, it was important to note that the bridge is still "compromised", so loads on it will need to be managed carefully.
"This will remain until the permanent solution is in place and the bridge can support its full weight capacity again."
Auckland Transport, meanwhile, said there had been a big shift to buses and ferries since Monday as people viewed public transport as an attractive option to beat congestion.
There were still plenty of seats available on regular services, especially on the Northern Express bus routes to and from the North Shore.
The travel time by bus from Albany to the CBD this morning was just 25 minutes, and almost double that in private vehicles.
Ferry passengers increased 104 per cent compared to last Tuesday and the busy Devonport service was returning to a half-hour off peak schedule.
Bus patronage on Tuesday compared to the previous week was up 5.4 per cent after an 8.2 per cent increase on Monday.
Auckland Transport said the trend of people commuting earlier and off-peak increased on Tuesday.
With the opening of the additional bridge lanes, the northbound bus priority lane that had been in place for the past two days at the Fanshawe St motorway on-ramp was relocated to the left of the on-ramp to help provide more reliable travel for people on buses.
The Curran St northbound motorway on-ramp has been reopened to traffic.
AT advised those who needed to travel by car to use the Western Ring Route via SH16 and SH18 as an alternative to SH1 and the bridge.
"Plan ahead, allow extra time and use the online journey planner apps to check which is the least congested and quickest route before leaving home."
Testing carried out using heavy vehicles before bridge reopened
The crew involved in the overnight work carried out real-life tests to ensure the bridge was performing the necessary design specifications and requirements, NZTA said.
Heavy vehicles were brought in for that testing.
However, no overweight vehicles are allowed across the bridge at the moment - and they are being asked to stay away until the permanent fixis installed.
Work is now moving towards a permanent repair to reopen the bridge entirely. But NZTA warned that could still be "weeks away".
The bulk of that permanent solution involved the calculation and peer review of the new permanent strut in relation to how it will affect the performance of the whole bridge.
"This includes careful calculations on how to rebalance its load-bearing function.
"The new modelling is necessary because the materials of the new structure will not exactly match those that were installed 60 years ago.
"Teams would monitor the performance of the bridge every day."