In a few months’ time the business case for the CBD rail tunnel will be completed, and we will see just how well the project ‘stacks up’ in terms of being value for money. There’s no doubt that it’s an expensive project: with a likely cost of at least $1.5 billion (similar to Waterview Connection and the Holiday Highway), so therefore assessing its benefits is crucial. What impact will the project have on Auckland, and how do we ‘capture’ that impact to help justify the obviously large cost of it?
The traditional method of analysing the benefits and costs of public transport projects is outlined in NZTA’s economic evaluation manual, volume 2, and appears to be largely based around the benefits to road-users (through reduced congestion) that happen when you take someone off the road an onto public transport. Because rail trips tend to be quite long, and tend to travel through some of the most congested parts of the road network (ie. into the CBD), their ‘de-congestion’ benefits are quite significant. This is outlined in the table below:
But really that’s only part of the story when it comes to what the real impact of the CBD rail tunnel is. Yes, it doubles the capacity of Britomart, which enables us to run many more trains and therefore makes it possible for patronage to increase (and therefore we capture all those de-congestion benefits) but there are also other benefits that I think need to be considered.
Like the effects on the CBD itself. You only need to look at the area around Britomart station to see that the station has prompted significant redevelopment, intensification and a concentration of economic activity over the past seven or so years the station has been open. Imagine something similar, although potentially on an even bigger scale (given that half of Britomart’s catchment is sea) around the Midtown, Karangahape Road and Newton stations and you start to see the impact the project could have: encouraging businesses to locate in the CBD and generating real wider economic benefits, not the kind of rubbish “pull a number out of a hat” wider economic benefits we’re seeing used to justify the holiday highway.
Furthermore, if we look a bit more long term projects like the CBD rail tunnel begin to appear as quite essential if we want the CBD to really grow and develop Auckland into a ‘world class city’. I’m not sure of the exact numbers, but I think around 80,000 people currently work in the CBD, and probably most of them arrive some time between 7am and 9am and leave during an evening peak time that might be a little more spread out, but would generally be between 4pm and 7pm. Add in the many thousands of students attending Auckland University and AUT (as well as the many private education schools in the CBD) and there are a lot of people shifting in and out of this space, particularly at peak hour. At the moment around 48% of those who do enter the CBD during peak times do so on public transport, as shown in the table below:
Realistically, there is little or no road capacity into the CBD at peak times available. All the motorways into the city are pretty clogged, most of the arterials that support those motorways are clogged and so forth. So basically, in order for the CBD to grow then more public transport capacity needs to be provided – because the roads are clogged and it would be damn near impossible to add road capacity. Does this “enabling the CBD to grow” get captured by the business case analysis? I don’t know. Should it? Absolutely.
Another issue that I think needs to be taken into consideration is the fact that unless we build the CBD rail tunnel, any other expansion of the rail network is impossible. By early next year we will be running 20 trains into Britomart per hour in the morning peak, and because all those trains have to also exit via the same tunnel, we won’t be able to go beyond that. 20 trains per hour basically consists of 10 minute frequencies on the three main lines plus two trains from Onehunga. That’s it. After early next year of course the trains will get longer in the future so we can add passenger capacity, but basically the system is at ‘train capacity’ until the CBD tunnel is built. This means we can’t have an airport line without the CBD tunnel, we can’t have inter-city trains to Hamilton unless we remove that slot from the suburban trains, we can’t go beyond 10 minute frequencies… we can’t really do much at all with the rail system. Does the “this project allows for further expansion of the rail network that is impossible without it” benefit get captured by the business case analysis? I don’t know. Should it? Once again, absolutely.
It will be very interesting to see the business case for this utterly critical project once it’s complete, and I very much hope that somehow these ‘wider’ benefits of the CBD rail tunnel are being taken into account. I do worry at the narrowness of cost-benefit analyses at times, usually because I think “I wonder why the cost-benefit ratio of Britomart station would have been when it was proposed?” Answer: probably extremely low because hardly anyone used the rail system then. Does that mean it was a poor investment? Answer: couldn’t be further from the truth.