Every weekend we dig into the archives. This post by Peter was originally published in September 2014.
Back in July former World Bank urban planner Alain Bertaud and his wife Marie-Agnes, a fellow professional in the field, came down to New Zealand at the invitation of the NZ Initiative and the Minister of Finance’s office to deliver a series of talks on urban economics. He had a number of thought-provoking things to say to urbanists of all stripes – a message that was very much in line with Transportblog’s core principles and big ideas.
While Bertaud is sometimes cited as a proponent of low-density urban sprawl and motorway development, his arguments about urban development were nuanced and thoughtful. The Bertauds are, after all, urbanists themselves. They have chosen to live in vibrant, dense, and diverse cities – Paris, Washington, D.C., and lately New York. (That’s a revealed preference if I’ve ever seen one – they certainly don’t live in Houston!)
In addition to seeing Bertaud’s talk , which is available online here (pdf), I was lucky enough to sit in on a smaller discussion section with other professionals in the field. I took three key messages away from the talk and the conversation.
First, cities are labour markets. We often forget this fact, even though it’s the reason we have cities at all. Cities are the physical expression of agglomeration economies, or the productivity advantages of locating near other people and businesses. In Bertaud’s view, ensuring the efficiency of urban labour markets means ensuring that people can access a large number of jobs from their homes.
As a result, he argued that urban and transport planning should aim to keep down commute times. He recommended looking at two key measures – first, the number of jobs available within a 30 minute drive, and second, the number of jobs available within a 45 to 60 minute public transport journey. Here, for example, is his analysis of commute times in Singapore and the US.
Bertaud didn’t recommend any specific policies to reduce travel times, although he spoke positively about Singapore’s use of demand-responsive road pricing and development of an expansive metro network to reduce average travel times. As a transport economist there are a couple of key observations I’d make on the topic:
- Building more roads is not a good way to reduce travel times. Induced demand – people driving more or moving further out of town in response to new road capacity – usually eats up the forecast travel time savings. In short, people travel more but they don’t travel any faster. If you want to actually reduce driving times, the only way to do it is to introduce road pricing.
- Cities with reasonable densities and an underdeveloped public transport network – like Auckland! – are in a good position to improve employment accessibility through investments in rapid transit networks and better bus networks. Fortunately, Auckland’s pursuing this approach.
- In light of induced demand, the best way to improve the accessibility of jobs may be to simply make things closer together. The efficiency of dense urban environments is often underrated. For example, although the roads in downtown Manhattan are far more congested than Houston’s, Manhattan’s effective labour market is much bigger simply because everything is so close.
Second, we must plan for the cities that actually exist, not the cities that we wish could exist. Bertaud presented an excellent graphic to illustrate this point. It showed four kinds of cities – three that exist and one that does not (and can not):
Most cities that exist today are what Bertaud calls “composite cities”, meaning that a significant share of jobs are located in the CBD or in major centres, while other jobs are scattered around in industrial parks, neighbourhood shops, etc. In this city, people have a range of different travel needs. Many people need to get to large-scale, high-density employment hubs, which are efficiently served by rail lines and busways, while others are better off driving to more dispersed employment locations.
In short, real-world cities require a range of transport solutions, and they will not function well if one mode is unreasonably neglected. We don’t have to go far for an example of the perils of mode bias: the remarkable renaissance of the Auckland city centre, and its increasing contribution to New Zealand’s economy, would not have been possible without reinvestment in the rail system and the development of Britomart.
However, Bertaud criticised what he described as the “urban village” model, which hypothesises that if employment is dispersed evenly throughout neighbourhood centres then people will travel only to the nearest centre. This is a seductive idea – it promises to reduce travel distances by distributing employment. Unfortunately, it doesn’t exist in the real world because people have complex travel needs. Even if one member of a family chooses to live near where they work, their partner will often have to commute to a job further away.
We see this flawed idea pop up from time to time in New Zealand from advocates for suburbanisation. For example, people sometimes argue that we could reduce congestion by stopping growth in the city centre and relocating it to Manukau central instead. Aside from the fact that we tried this before and it failed, decentralising employment would only increase congestion from all the cross-town trips and reduce the efficiency of Auckland’s labour market.
We don’t have to go far for an example of the failures of the urban village model. Christchurch lost its city centre in the 2011 Canterbury Earthquake, and employment dispersed throughout the city. Although the jobs have decentralised, the city now suffers from higher congestion as it can’t run efficient bus services or provide enough road capacity.
Third, it’s important to ask whether planning regulations are restricting development in areas that are accessible to employment and amenities. Economists in New Zealand have spent a lot of time talking about Auckland’s metropolitan urban limits while paying little attention to regulations in the rest of the city. Bertaud argues that limits on density, such as building height limits or minimum lot sizes, can price out the poor from accessible areas. Incidentally, this may be happening in Auckland – my research found that poorer people tend to live further from employment hubs and commute longer distances as a result.
Bertaud said that when he was advising developing-world cities on planning policies, he’d often start by creating a map of the minimum lot size required by existing rules and estimating what share of the city’s population could afford that amount of land. Here, for example, is his map of floor-to-area ratios in Mumbai, India, which shows that in most parts of the city people are required to buy 1 square metre of land for every 1 square metre of dwelling they want to build. As land is quite expensive in Mumbai, this is basically a policy that requires the poor to get out or build illegally:
It would be fascinating to see a similar map for Auckland if anyone wants to have a go…