More cites are putting in bike lanes, but are they safe enough?

Many cities have had standard bike lanes for years, but these are being replaced by “green lanes,” which are bike lanes separated from traffic by curbs, planters, posts, or parked cars.

Do green lanes reduce accidents?

Well it depends on who you ask.

A lawyer in New York City sued against a bike lane that reduced traffic lanes from three to two. He says that contrary to what the city says, the green lanes have resulted in more crashes and injuries.

A survey in Washington D.C. found that cycling crashes increased since the two-way green lane on 15th Street opened, but then again the number of riders biking there more than doubled, so the actual rate of accidents remained the same.

The “American Journal of Public Health” article reports on crashes before and after 43 miles of standard on-street bike lanes were installed in New York City between 1996 and 2006.

Crashes included in the study were total crashes, bicyclist crashes, pedestrian crashes, multi-vehicle crashes, and injurious or fatal crashes. They concluded that the installation of bike lanes was not associated with an increase in crashes; in fact for all type of crashes except bicyclist crashes, there was a decrease after the installation of bike lanes.

They could not control for increasing volume of bicyclists, which could affect the number of crashes, because they did not have that data. However, data from a New York City survey indicate that there was a 51% increase in bicycle volume between 1996 and 2006 and a 48% increase between 2006 and 2008.

The researchers say that if they had been able to control for volume they may have seen a significant decrease in the number of crashes that took place in areas with bike lanes. Still it appears that intersections – where bike lanes stop – are dangerous places.

The researchers suggest using “bike boxes” and other markings that indicate the path of the bike lane across intersections.