Lloyd Alter, April 11, 2014
Nate Silver's FiveThirtyEight is the go-to site if you are a stats geek. Planner Gretchen Johnson and MIT PhD candidate Aaron Johnson munch the stats on bike lanes to answer the question: do bike lanes increase car traffic congestion? It's an important issue; whenever bike lanes are proposed (or a politician like Toronto's Rob Ford, who hates them, gets elected) the complaint is that obviously, if you take space away from cars it is going to slow down traffic. Except it is not so obvious.
After studying stats from Minneapolis and Brooklyn, they found that for roads which were near full capacity during peak hours, there was a noticeable increase in congestion when lanes were removed. But not all streets are at full capacity.
Now a lot of anti-bike lane types might use this as an excuse to say "go build your bike lane somewhere else, our road is at capacity," but on the very controversial Prospect Park West bike lanes, where this was an issue, they found that the installation of bike lanes didn't slow traffic much at all. They also found there were other benefits:
There are also a lot of bike activists like me who would point out that who cares if drivers face a little more congestion and a minute or two longer drives, the roads are for everyone and not just cars. But that is another argument altogether.
A useful new weapon in the war on the car at FiveThirtyEightSource: treehugger.com