Ask Phoebe: Maioro St interchange upgrade necessary for the development of Western Ring Route

Interchange between Maioro Street and the Southwestern Motorway being built years ago. Photo / Natalie Slade

Q: Many millions were spent by NZTA building SH20, to the current run off at Maioro St.
In the past few months the road heading north from Dominion Rd to Maioro St has been ripped up, extra construction added to the left side and the road moved over, leaving a very rough road surface.

It also appears they are building more strengthened barriers in the middle between northbound and southbound traffic.

Why is all this taking place, when the initial construction appeared so good?
Allen Grainger, Auckland.

A spokesman for the Transport Agency says all the work under way around Maioro St is part of a staged construction programme spanning several years to accommodate the development of other projects along the Southwestern Motorway. These projects include the Mt Roskill extension, the upgrade of the Maioro St interchange (replacing the old roundabout with the present bridge), and the Waterview tunnels.

There will be an extra northbound motorway lane, and the existing off-ramp lanes are being moved further left to allow traffic to head towards the tunnels safely. The Transport Agency says doing this work earlier and leaving it unused for a long time would have been uneconomical and unsafe.

Five new overhead sign-bearing gantries leading up to the Maioro off-ramp are also being constructed to give people plenty of warning to be in the correct lane to exit at Maioro St, or to continue on the motorway. This work requires building new gantry bases in the median between north and southbound traffic. It has also required closing the Ernie Pinches footbridge so it can be lifted and lengthened. When all the work is finished, the Transport Agency will resurface the highway.

Q: I've never seen the traffic lights on the onramp from Fanshawe St to the Harbour Bridge working. Have they ever been turned on? If not, how bad would the traffic have to be for them to turn on? Gary Lowndes, Auckland.

The Transport Agency says the ramp signals here do operate to help traffic flow safely during the morning, when two of the northbound motorway lanes through St Marys Bay are switched temporarily to provide extra capacity for people driving south into the city from the North Shore. The signals usually operate between 7.30am and 11am, and help create gaps in northbound on-ramp traffic so that it can merge smoothly with vehicles coming through the Victoria Park tunnel. The Transport Agency says it will operate the ramp signals at other times if there is an incident or an event.

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