Few ideas have proven more powerful in shaping Canadians' thinking about urban transit than this: Building roads is self-defeating. Like those famous South Sea Islanders who built crude wharves thinking that it was the wharves that caused cargo ships to appear and unload valuable goods, those holding this view believed that building highways could never solve our transit woes because the mere existence of the roads would conjure up more cars.
This theory drives much of our preoccupation with building highly expensive urban transit – subways, light rail, dedicated bus lanes and more – because, the argument goes, we break the cycle of dependence on the car and cut congestion by shifting resources away from road building and into transit.
Except it's not true. As urban geographer Wendell Cox likes to say, this idea that road construction only worsens congestion is like believing that building more maternity wards will cause more babies to be born.
This connection between road construction and congestion has been most comprehensively studied in the United States. There, 30 years ago, the Texas Transportation Institute at the Texas A&M University created an annual Travel Time Index (TTI) that estimates how much time traffic congestion adds to commuting by comparing actual travel times of commuters in different cities with the time it would take to travel the same distances in the absence of congestion.
Over the decades of its existence, the TTI has revealed some fascinating shifts. In the early days of the index, Phoenix, for example, had the 10th worse congestion among major urban areas in the U.S., despite being only 35th in population. It has more than doubled in size in the ensuing decades (it is now the 12th largest urban area in the U.S.), but its traffic congestion has fallen to 37th.
What explains this major improvement? A huge expansion of public transit? Hardly. Try a major road-building program. Something similar happened in Houston.
At the other end of the spectrum, Portland, Ore., has pursued road-skeptical policies similar to many major Canadian cities. The result is markedly worsened commuting times. According to the TTI, over the past 30 years Portland has gone from having the 47th worst congestion in the U.S. to the sixth worst.
Now data are starting to emerge that allow us to compare commute times among similar rich-world industrialized countries in Western Europe, the U.S., Canada, Australia and New Zealand. The results are not encouraging for the anti-car crowd. The worst urban congestion in this group of countries is in New Zealand, followed by Australia, countries that have invested relatively little in urban highways.
Canada comes third, with the rankings showing the average commute in Canada takes nearly a quarter longer than it needs to due to congestion. My hometown of Vancouver takes the cake for the worst performance in North America (worse than Los Angeles!) and third worst among all the countries surveyed. Toronto has nothing to boast about, with the sixth-worst performance in North America.
Counterintuitively for most Canadians, who believe American cities are largely highway-shaped parking lots, the U.S. has the best performance over all, with the average commute lengthened by less than 20 per cent by congestion. It also has only four cities in the list of 20 most congested, but 15 out of the 20 least-congested cities in all those studied.
Of course road-building isn't the only thing that distinguishes American cities from many of these international peers ranked in the data. According to Cox, two other factors matter hugely. One is that U.S. cities tend to be less dense than cities elsewhere, and jobs are more widely dispersed throughout American cities.
This relationship between density and travel times is another counterintuitive puzzler for those who believe cars and roads are the problem, rather than the solution to transit woes. How easy it is to assume that travel times must be shorter where cities are dense and people therefore have shorter distances to travel to work.
What the real world shows us, though, is that when urban population density is lower, and jobs widely dispersed rather than concentrated in a city centre, commuter traffic is more widely scattered on the road network, lowering commuting times. This is a real challenge for the advocates of heavy investment in subways and light rail, which are reliant on commuting patterns focused on a hub-and-spoke model bringing workers downtown along densely developed transit corridors.
A good New Year's resolution for much of Canada's urban planning elite, then: Remember "urban sprawl" is not a problem to be solved, but part of the answer to how vast numbers of people can live together in big cities without life grinding to a halt in traffic.