David Farrar notes that 4 of the 10 worst congestion points in New Zealand are in Wellington. He concludes “Transmission Gully will help with some of that, but not all”. Quite the opposite, old boy. Transmission Gully will not create any new capacity at any of these congestion points. In fact, NZTA says it will create more traffic heading into 3 of them.
Here’s the list of Wellington’s top congestion points from the top ten:
4. Johnsonville to Porirua Motorway from Takapu Road to Westchester Drive (Wellington)
6. Western Hutt Road (Wellington)
7. Wellington Urban Motorway (Wellington)
10. Centennial Highway between Johnsonville and Newlands roads (Wellington)
4, 7, and 10 are all citywards of where Transmission Gully joins the existing State Highway 1 motorway. It does not bypass any of them.
NZTA says that Transmission Gully would result in 8% more traffic per day at Tawa – 4,400 more traffic movements a day heading in and out through those 3 congestion points.
This is called induced traffic. If you build big expensive motorways, it doesn’t relieve congestion, it subsidises sprawl and exurb living – meaning more people trying to drive into the city from further away each day.
That’s obviously a bad result for a country that already spends $8.3 billion a year importing oil (our entire current account deficit) but what happens when all that extra traffic tries to get through the existing chokepoints?
Worse congestion, of course.
And then some bright spark says ‘to realise the benefits of the billions we’ve sunk on Transmission Gully, we need to expend billions on adding new lanes to the motorway cityward of Transmission Gully’.
And, so, the cycle continues. Billions wasted on motorway projects that make no sense in their own right and, barely, make sense to get more value out of the previous generation of billion dollar motorway projects. You keep on spending more money trying to alleviate peak traffic but actually increasing it and pushing it around the system. And most of the time, the vast bulk of your motorway network sits idle because you’re building for these daily peaks.
The smart option is long-term integrated city planning designed to create neighbourhoods that don’t create huge amounts of peak traffic every day and transport networks that works sustainably. What we’ve got is piecemeal additions of motorway projects that do nothing to relieve congestion but make it worse.