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NZTA initiative provides relief on Southwestern Motorway


The NZ Transport Agency is increasing capacity for northbound drivers on the Southwestern Motorway [SH20] by providing an additional third lane on the existing Mangere Bridge.

The third northbound lane is due to become operational at 3am on Monday, 3 May, but the NZTA says the exact timing depends on the weather staying dry.    

The NZTA initiative means that a continuous three lane motorway will operate northwards from Walmsley Road across the Manukau Harbour to Hillsborough Road. 

“We anticipate the change will bring relief and time savings for drivers – particularly at peak times,” said the NZTA’s State Highways Manager for Auckland, Tommy Parker.  “The bridge with its previous two lanes was a pinch point on the Southwestern that caused of a lot of queuing, delays and frustrations.”

The extra lane has been added by reducing existing lane widths and moving the median barrier on the bridge.

Mr Parker says it is important that drivers observe the 80kph speed limit when using the northbound lanes. 

“It’s a motorway environment and the reduced lane widths and extra traffic on the bridge mean people have to drive with care,” he says.

The NZTA says if wet weather prevents contractors completing their final preparations for the changeover, the opening of the third lane will be delayed until later in the week. 

Mr Parker says the additional lane is an earlier than expected benefit that the NZTA and its partners constructing the new Mangere Bridge are able to deliver to drivers on this section of the Western Ring Route.    The project is 7 months ahead of schedule.

When fully complete in August this year, the new and existing bridges combined will provide extra capacity with fours lanes of traffic and dedicated bus priority lanes in both directions.  On either side of the bridges, there will be three lanes of traffic and dedicated bus lanes in both directions between Queenstown Road and Walmsley Road.