Putting a number of the cost of congestion in Auckland has become something of a perennial sport, with the mayor and business/infrastructure lobbies recently raising inflating it to as high as $3 billion. Those lobby groups wanted to back up their congestion cost claims and yesterday released a report by NZIER that throws a whole set of new numbers into the mix.
We have frequently been highly critical of past studies that try to put a number on this, usually because they have terribly simplistic methodologies and always compare against the crazy counter-factual of 100% free-flow conditions.
At first glance, this is a much more sophisticated study that typically avoids, or at least recognises, those pitfalls. For example, while the table above shows numbers for comparing current congestion levels against that unrealistic free-flow utopia, it says it would be stupid to aim for that, noting:
Targeting free-flow speeds (i.e. the speed limit) would not be an optimal use of the Auckland network as it would mean an under-utilised network.
To address that, it includes a comparison to a more realistic capacity measure that considers the optimal throughput of our roads. This effectively builds on and updates to current conditions the 2013 NZTA research report by Ian Wallis and David Lupton, which had an excellent methodology and pushed back hard against the crazy idea of using free-flow as a goal. Of course, this ignores that Level of Service (LOS) is a poor metric to use in an urban setting.
The report says that if our roads were operating their capacity during the week, we’d see economic benefits of between $0.9 billion and $1.3 billion. This is estimated at 1-1.4% of Auckland’s GDP which doesn’t seem all that high given the region’s economy has been growing by over 3% per annum for many years now.
Some of the broader economic and social impacts of congestion are calculated in a bit more detail than usually occurs with transport evaluation processes – Peter plans to look at this in a bit more detail in a forthcoming post.
While parts of the methodology appear strong, that doesn’t mean I agree with all the conclusions the report makes. In particular, the argument that congestion has major economic impacts, while seeming logical at a micro-scale, appears to be a long bow to draw when you look at different congestion levels of cities around the world.
If congestion seriously harmed economic performance, you would expect to see the economies of cities in the bottom left of the chart below struggling. But actually the opposite seems true – San Francisco, London, Singapore, Seattle and so on are thriving cities whose main challenge is providing enough housing to meet the needs of all the people that want to live in these places. I’d hardly think of Indianapolis, Adelaide, Canberra, Darwin etc. as being places for Auckland to seek to emulate.
Those bigger cities might be congested but they also have a lot of activity going on that can be achieved or participated in by using modes free from vehicle congestion, reminding me of this image.
The report also occasionally goes off and makes some bizarre statement, such as this on the Quay St cycleway which has had over 280k people use it over the last year.
However, the development of other modes of transports can add to congestion on the roads. For example, the development of cycleways has seen the removal of bus stops including main stops which pick up passengers at key tourism operations such as the ferry terminal where cruise ship passengers alight.
Of course, this isn’t to say we should just ignore congestion, and putting a number on the cost of it isn’t really the key issue. It’s also interesting to note that at around $1 billion per year, this cost is around half of what gets spent in Auckland on transport (which seems to suggest our current approaches to “fixing” congestion aren’t working). The key issue is the best way of doing something about it. Of course this why it’s so important to improve walking and cycling options and the Congestion Free Network, which provides people with a way of avoiding congestion.