I found myself in an interesting discussion on Twitter yesterday about the Northern Busway and whether a North Shore railway line is likely to be necessary at some point in the future or not. This is a fairly common debate, but one that’s often a bit ill-informed by the assumptions that people make. Things like:
- Rail to the North Shore is really expensive. Well yes it is, but not nearly as expensive as building a $5 billion road tunnel.
- The North Shore already has a busway, why does it need a railway line? And here’s where things get interesting – read on!
While the North Shore certainly does have a busway – a very successful one at that – we must remember that the busway proper is only between Constellation and Akoranga Stations in both directions, then between Akoranga Station and the Onewa Road interchange in the southbound direction. In some other places there are bus shoulder lanes, but that’s it. When you actually start to map out how much of the Northern Express route (the core route along the busway) is busway (blue) bus lane or shoulder lane (green) and mixed traffic (red) the result is actually somewhat surprising:Breaking down the distances, you can see that northbound passengers in particular get a pretty raw deal:Total it all up and you actually find that only 41% of the Northern Express’s route is actually along the busway proper. A full 40% of the route is without any form of bus priority measures at all – including half of the route for northbound buses. Most worryingly the places with some of the patchiest bus priority measures, like the Harbour Bridge, St Mary’s Bay for northbound traffic and around the Britomart departure points are the very places where bus volumes are the highest and the competition for road space is most intense, with buses sadly losing out. For example, the fact that NZTA didn’t bother to put a northbound bus lane through St Mary’s Bay when widening that motorway speaks absolute volumes of the disdain that organisation has for public transport.
The point of all these calculations isn’t to criticise the Northern Busway, but actually to point out that a railway line south of Akoranga – like the rail line shown below – wouldn’t actually duplicate much of the busway at all: just the southbound section between Akoranga and Onewa which would be very handy for minimising the length of a cross-harbour tunnel:Furthermore, this is pretty much exactly the same section which NZTA’s Additional Waitemata Harbour Crossing Project adds capacity to – at a cost of at least $5 billion (a rough estimate based on past analysis suggests that a Takapuna to Aotea rail link should be able to be built for under $2.5 billion). After all, the only thing AWHC does is shift ‘through-traffic’ off the harbour bridge into a new tunnel and then turn the harbour bridge into giant on and off ramps feeding a heap of cars into downtown that we don’t actually want. For $5 billion!
Clearly in the meanwhile there are things we can do to improve the busway and increase the measly 41% total. An extension northwards from Constellation to Albany is a no-brainer. Improved priority measures in the inner city is another clear requirement, plus we need to do something about getting a bus lane northbound through St Mary’s Bay. But for goodness sake, before we go and spend $5 billion on a road tunnel that’ll do nothing but feed cars into downtown, can we consider a much cheaper and much more effective alternative?