Contractors are ready to start a $30 million project to widen one of Auckland's most clogged traffic routes, between New Lynn and the Southwestern Motorway.

Although Auckland Transport has announced today as the start date for turning Tiverton Rd and Wolverton St into a four-lane arterial route, it will probably be next week before motorists see the first orange traffic cones along the 2.2km route.

What is now mainly a two-lane bottleneck carries an average of 31,400 vehicles a day, posing a challenge for lead contractor Downer NZ to keep traffic moving during almost two years of widening.

Traffic volume has grown more than six times since the Southwestern Motorway was extended three years ago, pouring a constant stream of cars each day onto what has become the preferred route for many Waitakere residents who drive to work in South Auckland.


Auckland Transport hopes one lane will be kept open in each direction as much as possible, and says the most disruptive work will be left for the quiet Christmas period, although the speed limit will be reduced to 30km/h.

The project will include removing a dangerous roundabout at the route's intersection with Blockhouse Bay Rd, and installing five sets of traffic lights which the council transport body promises to synchronise to minimise delays.

The bottleneck was created because of cost cuts in 2007 by the former Auckland City Council, which spent $3 million widening a difficult section of Tiverton Rd before deferring the rest of what was then a $17 million project until after last year's Rugby World Cup.