Frequently Asked Questions

Q: Why do you want to make 8th Avenue and Prospect Park West two-way?

A: Restoring 8th Avenue and Prospect Park West to two-way traffic flow will have multiple benefits. It will reduce the speed of vehicles on both roadways, where speeding is currently a common problem. It will improve the overall flow of traffic by creating another access point to Grand Army Plaza from the south, alleviating the frequent gridlock conditions at 8th Avenue and Union Street, and will reduce traffic on 15th Street between Bartel-Pritchard Square and 8th Avenue. Most importantly, it will increase safety for pedestrians and bicyclists, due to the decrease in speeds and more orderly flow of traffic. There's quite a bit of research indicating that two-way streets are safer for pedestrians.

Q: How do two-way streets cause a reduction in speeds?

A: Vehicle speeds are generally slower on two-way streets because of “friction,” or the effect of cars passing each other in opposing directions. In addition, because traffic lights can’t be sequenced in one direction, vehicles are unable to travel for extended distances without encountering a red light.

Q: Are there other benefits to two-way streets?

A: Yes. Two-way streets reduce the number of vehicle miles traveled, because drivers can get directly to their destinations without having to go blocks out of their way. With people searching for parking responsible for so much of Park Slope’s traffic (45%, according to a 2007 study [PDF]), converting one-way avenues into two-way avenues could have significant benefits, both by reducing potential for vehicle-pedestrian conflicts, and enabling drivers to get to their destinations more directly and quickly.

Q: Won’t replacing a travel lane on Prospect Park West with a protected two-way bike lane create congestion?

A: No. Prospect Park West clearly has more capacity traffic capacity than it needs, which contributes to speeding. Restoring 8th Avenue and Prospect Park West to two-way traffic flow won’t affect the number of northbound travel lanes (one on each avenue instead of two on 8th Avenue) and the two southbound travel lanes (one on 8th, one on PPW) should easily accommodate current traffic volume.

Q: Aren’t these roads too narrow to be made two-way?

A: No. Even with a lane given over to a two-way protected bike lane, Prospect Park West will be approximately the same width as 6th Avenue at its widest points (south of Carroll Street). 8th Avenue is the same width or wider than 6th Avenue at its narrowest points (north of Carroll Street) and at its widest points (south of Carroll Street).

Q: Won’t converting Prospect Park West and 8th Avenue to two-way streets increase commute times significantly?

A: No. Park Slope Neighbors conducted a road test under controlled conditions to see how long it takes to drive (at the legal speed limit) from Union Street to 15th Street via both Prospect Park West and 6th Avenue, and from 15th Street to Union Street via 8th Avenue and 6th Avenue, in order to compare these one-way avenues with a two-way avenue. We conducted the test at night to control for traffic volume (we were able to travel unimpeded by other vehicles); we made sure we started from a red light each time; and we accelerated normally and used cruise control in order to drive at the 30-mile-per-hour speed limit when not braking for a red traffic light. The southbound trip took exactly two minutes and 57 seconds on both Prospect Park West and 6th Avenue. The northbound trip took three minutes and 20 seconds on 8th Avenue, and three minutes and 40 seconds on 6th Avenue. We repeated the drives in order to make sure conditions were consistent.