From $90m to $120m – and the perils of a three-lane tunnel

by Elaine Engman
The NZ Transport Agency has taken 14 days to respond to my question, but now I have their answer: the cost of the Buckle Street underpass and the memorial park has risen to approximately $120,000,000 instead of the original estimate of $90,000,000.

The width of the road in the underpass will be only 11.8meters for vehicles, plus about an additional 1/2meter on each side of the tunnel for concrete protective barriers.

A two lane underpass without a flyover could improve traffic flow because the stop-start lights at Tory Street will be eliminated. But three lanes will be needed if the flyover is built, because both of its two lanes will feed into the underpass and a third lane will be needed for vehicles from Kent Terrace, Adelaide Road, Mt Cook and Tory Street – this underpass traffic will be compressed to only one lane to enter the tunnel.

Since the width of the tunnel is only .4 meters wider than the minimum width required for three-lane motorways, the combination of three lanes of cars, trucks and buses (some of which will need to change lanes in a short distance if they are planning to turn on to Taranaki Street) makes accidents and “pinch points” very likely.

The speed limit will supposedly be 50kmh, but drivers on the flyover will be tempted to go faster because traffic coming out of the Mt Victoria Tunnel will be going from one to two lanes and the flyover will be downhill.

If the tunnel is blocked or even crowded, cars could be left waiting on the flyover. What is the sense of building a flyover that will not only be an ugly, outdated eyesore, but will also probably cause more accidents and may well increase congestion at peak times?

I spoke of these issues in my submission to the flyover board of inquiry last month.

Unless there is an accident, traffic flows very smoothly round the Basin except for some backups around rush hour. Having lived in Southern California for 49 years and then the Netherlands for 17 years, I do not see how 5 or even occasionally 10 minutes of slowing at rush hour can be viewed as a “terrible traffic problem.” More importantly, the flyover will do little or nothing to improve traffic flow.

My partner’s end unit apartment in Tasman Gardens has windows overlooking the Basin, Memorial Park tunnel and Massey University. Therefore we have a perfect view of the backup of traffic every day on Buckle Street. When the traffic round the Basin is very slow, either there has been an accident or there is a back up of traffic trying to get on to the motorway via Buckle Street. The new tunnel under Memorial Park will do little to improve these matters.

Some slight improvement should be noted with the elimination of the traffic light at Tory Street, but there will still be 3 more traffic lights before cars reach the Terrace Tunnel. I thought that the work to widen the road from Taranaki Street to the Terrace Tunnel would improve traffic flow at rush hour, but that does not seem to be the case.

The Basin Bridge/Flyover will not significantly improve traffic flows, it will be a permanent eyesore and a waste of taxpayers’ money.

This article uses parts of two submissions made to the board of inquiry which has now completed its hearings.

Read also
Deceptive about flyover costs

 

1 comment:

  1. Traveller, 6. June 2014, 20:36

    The enormous cost increase points to a similar financial blowout if the flyover is allowed. The NZTA has a poor track record of effective budget management in central Wellington.

     

Write a comment: