KEY POINTS:
Final links will open today and tomorrow on Auckland's Spaghetti Junction, offering drivers direct connections between its contributing motorways - but with a catch.
A $207.5 million refit of what Transit NZ calls the Central Motorway Junction gives traffic access from the Northwestern Motorway or the port to the harbour bridge without jamming local streets.
Links the other way - from the bridge to the port and the Northwestern Motorway - opened a fortnight ago.
This morning should start quietly with the opening of the northbound link from the port.
Tomorrow will be the turn of the long-awaited motorway-to-motorway connection for commuters heading from western suburbs to the North Shore.
"If you're travelling from Western Springs to North Shore, you'll get on at St Lukes and stay on all the way," Transit chief Rick van Barneveld told guests at Friday's opening ceremony in a marquee on the glistening black tarmac of a ramp built for northbound traffic joining the motorway system from Parnell and the port.
"There'll be no need to get off at Nelson St and local roads like Ponsonby Rd, Union St and Hobson St will be freed up."
But the catch will be a traffic management technique, in which red and green lights called ramp signals will control the flow of vehicles from the northbound links to State Highway 1.
The signals, looking just like traffic lights, will turn themselves on when sensors in the tarmac indicate heavy flows in the receiving motorway.
Vehicles will have to wait to be released one by one before joining the mainstream, and drivers will risk $150 fines if CCTV cameras catch them running red lights.
Signals will control traffic from the port and the Northwestern Motorway after it merges into one ramp towards the Northern Motorway, and will be ready to be turned on from this morning, although drivers will probably not get their first taste until the afternoon peak. Other signals will also be introduced today at northbound ramps from Wellington and Curran Sts.
Although Transit says the signals will help to relieve congestion by ensuring less disruption from merging traffic, it may have trouble convincing drivers who are fed up with delays on the Victoria Park viaduct.
Those delays are not new, and Mr van Barneveld said until a $320 million northbound motorway tunnel opened under Victoria Park in about 2012, the signals would be essential for managing traffic at the bottleneck.
"So we hope Aucklanders will work with us to get used to this, and our commissioning over the Christmas period is a crucial time for the region to do that when we don't have peak traffic flows."
Mr van Barneveld paid tribute to the workers and contractors in what was not only Auckland's largest roading project but its most complex in the level of engineering cunning needed to squeeze the extra links under and over existing motorway sections within a tight corridor.
"People have painfully extended viaducts by a metre here and a half-metre somewhere else to achieve curves people can drive safely through and see around and be able to stop before they bang into other vehicles.
"These improvements are to ensure more consistent speeds, simpler decision-making for motorists and better management of congestion."
Pasta la vista, says Transit
Transit wants to change the name of Spaghetti Junction.
The road building agency's chief, Rick van Barneveld, said: "We took the view at the start of this project that, if we kept calling it Spaghetti Junction, people would think we'd just finish up with more spaghetti. We made a conscious choice to re-label it Central Motorway Junction. I hope, over time, we'll lose sight of Spaghetti Junction."
That brought good-humoured jibes from Auckland Issues Minister Judith Tizard and Auckland City Mayor Dick Hubbard, who heaped praise on the project but insisted Spaghetti Junction was an affectionate term Aucklanders would never relinquish.
