Serious traffic delays in Auckland last night were blamed on cautious and curious drivers travelling through the new Victoria Park tunnel after two lanes were opened yesterday.
Although the Transport Agency said there was no extra traffic on the motorway, cars and trucks were backed up to Otahuhu by about 5pm to reach the 450m tunnel, which replaced northbound lanes on the Victoria Park viaduct.
Agency regional assets manager Steve Mutton blamed the delays on drivers adjusting to the new environment of the tunnel and hoped they would not be as severe through tonight's evening traffic peak.
Even at about 4pm yesterday, before the start of the evening rush hour, it took a Herald car 13 minutes of queuing to reach the tunnel from the Northwestern Motorway.
But once in the tunnel, it was a smooth ride, even at only half of a temporary traffic limit of 70km/h.
Bright lighting inside the tunnel matched the sunshine outside before it tapered off towards the end to allow drivers' eyes to adjust to daylight again when emerging at the Westhaven end of St Marys Bay.
Although the northbound-only tunnel has three lanes, Mr Mutton said the agency was unable to open it to full capacity for the 55,000 vehicles travelling through it each day until it could complete motorway works along St Marys Bay by March.
He said the third lane would remain coned off until the bridge's moveable lane barrier could be brought to the northern end of the tunnel to manage traffic emerging from the tunnel.
That could not be done until work was completed on widening the surface motorway through St Marys Bay by one lane in each direction - an integral part of the $406 million project.
"This is the first stage of quite a large project - it's a phased project, it's a sequence of works," Mr Mutton said.
He was aware of delays of 30 minutes in reaching the tunnel yesterday but expected those to ease in coming weeks as drivers adjusted to the environment.
"It's new infrastructure and from our experience on new projects, it just takes a few weeks for people to get used to the new environment.
"People are looking at the tunnel as they drive through and getting used to that new layout - as soon as they become familiar with that environment, we're expecting to see it go back to the normal flow."
He noted that the two lanes which opened yesterday were not intended to increase capacity through the Victoria Park bottleneck.
They matched two northbound lanes on the overhead motorway viaduct which were closed to allow contractors to reconfigure them to take southbound traffic from January.
But when the tunnel and widened motorway opened fully, as the first of the Government's seven "roads of national significance", there would be an extra three lanes of capacity through Victoria Park, as all four lanes of the overhead viaduct would carry southbound traffic.
Mr Mutton promised motorists "a huge improvement in journey times" once the project was complete.