On FifeThirtyEigth Gretchen Johnson and Aaron Johnson wrote an interesting article about whether or not bike lanes have a negative effect on traffic. While these days more and more cities ike New York City, San Francisco and Chicago also take the bicycle drivers into account, the question arises if they actually make traffic worse. Bike lanes are in the planning or construction phases in Louisville, Ky., Raleigh, N.C., the Buckhead neighborhood of Atlanta, Ferndale, Mich., Rutland, Vt., and Elyria, Ohio so that it is a valid question to ask if these projects are an good idea. From an ecological standpoint this is certainly true, but if environmental projects should have a wide acceptance, the changes should not have a negative effect for the population. The question of increased congestion caused by new bike lanes has come up frequently in New York City since June 2010, when the city’s Department of Transportation built a protected bike lane along a 1-mile road, Prospect Park West in Brooklyn. So Johnson & Johnson analyzed Minneapolis, which Bicycling magazine has recognized for several years as the best city for biking in the U.S. as well as New York City’s rospect Park West bike lane. Here is what they found:
We can confirm our conclusions about the post-bike lane level of congestion on Prospect Park West with New York City’s Department of Transportation’s final metric. Somebody got in a car and actually drove 19 blocks down Prospect Park West, timing his or her trip during the morning and afternoon rush hours, and also during the middle of the day. The transportation department only attempted each trip once, so there’s not a lot of data for us to use in rigorous analyses. However, the city found that there was no evidence that the travel times of the trips before and after the bike lane installation were any different, and we agree.9
The city’s report contains a number of other interesting statistics about the effect of the Prospect Park West bike lane. The number of cyclists using the road went up, and speeding cars, cyclists riding on the sidewalk and injury-causing accidents went down. The road diet isn’t just creating a space for bikers; it’s also making the street safer for other types of users.
It’s true that Prospect Park West is just one street in a city-wide bike lane project. However, urban planners have found similar benefits of road diets and bike lane installations in other cities, such as Cambridge, Mass.,Philadelphia, Seattle and St. Louis. Bike lanes, if they’re planned for the right streets, can be created without greatly increasing vehicular congestion. So, while opponents in Brooklyn may be right about fewer parking spots and a need to look both ways before crossing the bike lane, the data shows that this is only half the story.