The War on the Car crowd complains that installing bike lanes increases congestion and air pollution. In London, a peer in the House of Lords whinges “about the appalling increases in congestion and pollution caused by the introduction of bicycle lanes.” In New York City, politicians complain that replacing car lanes with bike lanes would “cause noise [and] air pollution”
New research presented by scientists at McGill University suggests that the construction of safe bike infrastructure could significantly reduce vehicle tailpipe emissions by offering potential motorists an attractive alternative to getting in their cars. Basically, it’s the “if you build it, they will come” philosophy many advocates lean on to champion bike infrastructure, backed up by scientists.
They studied the growth of cycling in Montreal since its installation of its significant bike infrastructure. The numbers don’t sound huge, “A reduction of close to 2% in GHG emissions is observed for an increase of 7% in the length of the bicycle network.” But it adds up; “This effect is as much as converting transit buses to hybrid and electrifying commuter trains.”
It's not just Montreal, either. Andrew Gilligan, London’s cycling commissioner under Boris Johnson, described the phenomenon more graphically earlier this year: (my emphasis)
Some people think traffic is like rainwater and the roads are the drains for it. If you narrow the pipe, they say, it will flood. If you block one road, they say, the same amount of traffic will simply spill over to the nearest easiest routes. But in real life, once the builders have finished, the spill never actually happens. The pipe doesn’t flood; some of the water goes away instead. Because traffic isn’t a force of nature. It’s a product of human choices. If you make it easier and nicer for people not to drive, more people will choose not to drive.
Now perhaps those McGill scientists can use this study to convince the university to stop banning bikes on campus.