The Environmental Protection Agency, bastard child of Nick Smith chaired by National crony Kerry Prendergast, has given draft approval to Transmission Gully. This billion dollar project returns 60 cents of benefits for every dollar spent. Worse than a night on the pokies. And that’s NZTA’s estimate assuming traffic growth that isn’t happening, and not accounting for $5 a litre petrol.
The Transmission Gully project, to be a net drain on the country of ‘only’ $400m, would need to start off with 21,000 vehicles a day and for that increase by 0.7% a year (and, then, it would have a design life of just 25 years before needing major repairs/upgrades). Basically, the country is being asked to fork out a billion dollars so that 10,000 people’s commutes will be ten minutes quicker each way.
Problem is, 21,000 a day is 87% of what currently passes the northern entry to the route every day – most likely, it is all the current traffic that goes from Mackey’s Crossing all the way into Wellington City. So, flawed assumption 1) Transmission Gully would take all the existing traffic off the existing coastal route. Next, that growth projection. Here’s how traffic volumes have changed since 2000:
That’s 0.14% on average – one fifth of the assumed growth rate. By the time this project is completed in the mid-2020swe will be looking at $5+ a litre petrol. That will mean in a reasonably fuel efficient car, the 27km Transmission Gully with its 180s ascent and descent in both directions will cost $10 each way every day. There’s no way that you’re going to have traffic growth accelerate to 5 times what occurred during the economic golden days of the 2000s in those conditions. Flawed assumption 2) rapid traffic volume growth in a world of $5+ a litre petrol.
Remember those flawed assumptions are necessary to keep the net loss to the country of Transmission Gully at ‘only’ $400m That means the real cost will blow out much larger.
The good news is that construction isn’t expected to begin until 2015. That means the incoming Labour/Green government can ditch the bloody thing and save us all a lot of money.