As a fairly simple measure that saves lives, bike lanes sure do raise a lot of ire. In Brooklyn, the addition of a two-lane bike path along the western edge of Prospect Park in 2010 sparked a legal battle that's still, after four years, ongoing.
Not so much. In keeping with previous research, a new analysis from the data-focused publication FiveThirtyEight finds that new bike lanes don't cause traffic jams, as long as they're put in the right place. Data from 10 streets in Minneapolis that measure the volume-to-capacity ratio (V/C ratio)—how congested a road is—showed that after the installation of bike lanes, congestion rose a little, but not enough to really slow down traffic:
Bike lanes don’t cause a lot more congestion if you put them on the right streets. If you cut down the size of streets that are already near capacity, you’ll create severe congestion. But if you start with roads that are well under capacity, you’ll only increase the congestion a little bit. And it may not even be noticeable.
And as for that infamous Prospect Park West bike lane? Data from New York City showed that it only caused mild congestion, meaning it might be just a little difficult to switch between lanes, but not bad enough for traffic to slow:
The city collected data at two different intersections of Prospect Park West (at Carroll St. and 11th St.) during weekday morning and afternoon rush hours and found that there were no changes in traffic volume...Some of the intersections were just above the level of mild congestion (V/C ratio ≥ 0.5), but not enough to affect the commute a lot. Just like the 10 streets in Minneapolis, Prospect Park West was still well under capacity during rush hour.
That little bit of congestion, it should be noted, is entirely by design. The New York City Department of Transportation has trumpeted its controversial Brooklyn bike lane as a traffic calming measure that has made the streets safer by slowing down cars.
According to the agency, data collected just a month after the lane was installed "indicate that speeding has been dramatically reduced, now fewer than one of every seven vehicles exceed the speed limit on Prospect Park West." So, bike lanes make it slightly harder for drivers to reenact 2 Fast 2 Furious. All the better.
[Image: Union Square, NYC via Flickr user NYC DOT]