I've posted before about the Green Party obsession with public transport being a "faith based initiative" that when you look a little closer, is not that rooted in reality.
Now according to the NZ Herald, Paul Minett of Trip Convergence Ltd, a company promoting carpooling, claims that three people travelling in a car can have a lower carbon footprint than if they travelled by bus, adding fuel to the call for the new expensive busway to be available to more vehicles. Now some of his claims involve double counting (e.g. the bus returning empty twice shouldn't be attributed to a single bus trip), but he is quite right that the claims about the low emissions of public transport over private motoring aren't as clear cut as the simple Jeanette Fitzsimons view of "bus good, car baaad".
The government's own Surface Transport Costs and Charges study indicated that, per person, the environmental costs of buses were double that of cars in the Auckland peak period (Table 3.4A of main report). Per vehicle a bus produces 18 times the environmental impact per kilometre than a car, which tells you how many people the bus has to carry on average to be even with a car. Think about how often you see buses running with less than that number. More importantly, traffic congestion increases the environmental impact of a bus or car in the peak period in Auckland by over 200%, so that is the real enemy costing time and fuel. Yes buses are getting cleaner and greener, but then so are cars.
So how about opening up the Northern Busway to other vehicles, with an appropriately high toll to keep it at a free flow? The other vehicles using it would save time and fuel, and there would be a few less on the parallel motorway. Oh and yes I know Transit's argument about not doing that until the Victoria Park widening project is completed - which in itself is a good reason to seriously consider tolls on the Harbour bridge and its immediate approaches to fund it.