Independent Researchers Prove Safety Effects of NYC Bike Lanes

The five boroughs of New York City have nearly 300 miles of bike lanes. Now, an independent study proves what most of us already figured out – that the bike lanes actually save lives.

An independent research team published “Evaluating the Safety Effects of Bicycle Lanes in New York City” in the June 2012 issue of American Journal of Public Health. They conducted a before-and-after analysis of 43 miles of bike lanes installed between 1996 and 2006 in the 5 boroughs of NYC.

What they found? Despite more people riding bikes in New York City, “with a 51% increase from 1996 to 2006 and a 48% increase from 2006 to 2008,” accidents did not increase.

Hardcore cyclists of yesteryear remember the lore of cycling before it was a generally acceptable means of transportation. Some were attracted to the grit and independence. They remember the danger – skitching off of trucks and carrying their bikes over the Williamsburg bridge before it was paved over. But for the average person, safety is an issue.

While the study can’t positively say that bike lanes reduced crashes, they definitely show that the “installation of bicycle lanes does not lead to an increase in crashes, even with the likelihood of a greatly increased number of bicyclists using these lanes.” The study reported that “if we could have properly controlled for differences in bicyclist volumes, we might have observed a significant reduction in crashes in the treatment group.”

The argument some Park Slope residents made when the Prospect Park bike lane was installed was that it was dangerous. Well, no dice.

Here’s their research summary:

Objectives. We evaluated the effects of on-street bicycle lanes installed prior
to 2007 on different categories of crashes (total crashes, bicyclist crashes,
pedestrian crashes, multiple-vehicle crashes, and injurious or fatal crashes)
occurring on roadway segments and at intersections in New York City.

Methods. We used generalized estimating equation methodology to compare
changes in police-reported crashes in a treatment group and a comparison
group before and after installation of bicycle lanes. Our study approach allowed
us to control confounding factors, such as built environment characteristics, that
cannot typically be controlled when a comparison group is used.

Results. Installation of bicycle lanes did not lead to an increase in crashes,
despite the probable increase in the number of bicyclists. The most likely
explanations for the lack of increase in crashes are reduced vehicular speeds
and fewer conflicts between vehicles and bicyclists after installation of these

Conclusions. Our results indicate that characteristics of the built environment
have a direct impact on crashes and that they should thus be controlled in
studies evaluating traffic countermeasures such as bicycle lanes. To prevent
crashes at intersections, we recommend installation of ‘bike boxes’ and markings
that indicate the path of bicycle lanes across intersections.

(Am J Public Health. 2012; 102:1120-1127. doi:10.2105/AJPH.2011.300319)

(Photo: Allison Burtch/ANIMALNew York)