The Auckland Harbour Bridge's centre span has been left severely damaged after a truck crashed into it on Friday.
But transport bosses say there are no risks of the bridge collapsing, instead a permanent solution was now being worked on to replace the damaged strut
Waka Kotahi NZ Transport Agency General Manager Transport Services, Brett Gliddon, said engineers were looking at a temporary solution this weekend.
The bridge was damaged on Friday morning after a southbound truck carrying a shipping container was blown sideways by a wind gust of up to 127km/h.
The damage has forced the closure of the middle four lanes of the bridge, with Gliddon saying it could be at least a week before cars could use those lanes again.
He asked for people who needed to cross the bridge to get to work to consider working from home while repairs were carried out.
The damaged section of the steel strut goes from road level to the top of the bridge. It was about 400 to 500mm square, with 15-20 bolts holding it in place.
Gliddon said it was safe for heavy vehicles to use both the northbound and southbound clip-on lanes.
Asked about additional public transport services he said Auckland transport are doing work over the weekend to make sure theres enough capacity.
"Timeframe for strut problem is several weeks. I expect four or five but it could be longer," he said.
"It may look like we're not doing a lot. I can assure people we are doing a lot, we've got people under the bridge, we've got people back in the office."
He added a permanent fix was definitely weeks, and not days, away.
"There will be additional congestion on the western ring so people need to be aware of that and take it into account."
Traffic around Auckland was brought to a standstill after the incident on Friday – with the long gridlock continuing into the night.
And delays were widespread in the lead up to the Auckland Harbour Bridge for both southbound and northbound traffic today due to the closure of the four middle lanes.
Auckland motorists had to spend up to seven times longer in traffic than normal yesterday after four lanes in the Auckland Harbour Bridge were closed following crashes.
That included a trip from Albany into the city's central business district taking between 50-and-70 minutes yesterday afternoon compared to a normal 12 minute off-peak commute, the Automobile Association said.
Peak hour trips lasted even longer with two Herald journalists taking one hour to drive three blocks from the top of Nelson St to the Victoria St intersection in the city centre.
National leader Judith Collins seized on the chaos with a promise to build a rail and road tunnel under the harbour to provide a second crossing to commuters.
Transport Minister Phil Twyford also backed a new harbour crossing, saying planning was underway.
AA's senior infrastructure advisor Sarah Geard said the traffic disruptions set to be caused by the lane closures were "another awful blow" to an Auckland just starting to get back on its feet after the Covid-19 lockdowns.
"What this underlines is that we really need to speed up the conversation about an alternative Harbour crossing," she said.
"It's unacceptable for one, relatively minor incident to have this much impact – Auckland needs a more resilient network."
Collins said her party, if elected, would get to work straight away on plans to build a road and rail tunnel under Waitemata Harbour, with actual construction to start in 2028.
"This will be New Zealand's biggest ever infrastructure project, and will require a huge amount of work – but it will be worth it," she said.
"Funding for Auckland's second harbour crossing was included in National's $31 billion transport infrastructure package, announced by Judith Collins in July."
Labour's Twyford also said a new harbour crossing was needed to ensure the city couldn't be brought to a standstill by a "freak accident" like that which happened yesterday.
"By the end of the 2020s, the Northern Busway ... is going to reach capacity and so we are going to need another harbour crossing," he said.
"And the planning and designation work on that is well underway. It is very likely to be a tunnel and it will include rail."
North Shore residents, meanwhile, were being asked to work from home next week if possible or to take the Northern Busway.
Auckland Transport said it would not be adding more buses to the Northern Busway but was confident it had room for plenty more passengers next week as it had "been sitting at around 50 per cent of normal pre-Covid levels".
"We will not be adding more vehicles as we don't have any additional buses due to our ongoing bus rail replacement programme," the agency said.
AT said its city bound Northern Busway buses running from 7am-9am Monday had in excess of 7000 seats currently while the Onewa Rd service had more than 2500 seats.
The return peak hour buses from 4pm-6pm had more than 6500 seats on the Northern Busway and 3000 on the Onewa Rd route.
"We are also planning to increase frequency outside of peak hours so that more customers can take advantage of our 30 per cent off-peak fare discount.," it said.
"Ferries are operating as usual and have spare seating capacity."
"We ask customers to travel off-peak if they can, plus plan ahead and allow extra time for their journey as there might be delays from joining the queues to cross the bridge. Also AT reminds customers to wear a face covering."
Those driving between south and north Auckland could consider using the Waterview Tunnel link to the Northwestern Motorway along with State Highway 18 to circle around the city through the west.
On Friday, NZTA said motorists would face delays for "several days and potentially weeks" after the damaged to the bridge.
"The truck striking the bridge has damaged the superstructure, with a steel upright sheared off," says 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."
NZTA said: "If you do need to travel motorists are urged to use the Western Ring Route (SH20, SH16 and SH18) around the harbour.
"The Western Ring Route has been planned and constructed to be used as an alternative to the Harbour Bridge, especially for trucks and heavy vehicles".
On average, more than 170,000 vehicles cross the Auckland Harbour Bridge on weekdays, with the configuration of the eight lanes changed four times a day to adjust to peak time traffic flows. With the four centre span lanes closed and only the clips ons open, there will be just two lanes in each direction.