Prospect Park West Redesign Puts the Brakes on Speeders

Park Slope Neighbors radar-gun study finds five-fold increase in adherence to 30-mph speed limit; 40 mph+ speeds cut by 95%

PARK SLOPE, BROOKLYN, August 2, 2010 – A radar-gun study conducted last month by Park Slope Neighbors has confirmed that the redesign of Prospect Park West has accomplished exactly what the New York City Department of Transportation (NYC DOT) intended – it's made the street appreciably safer by significantly reducing vehicle speeds.

The study, conducted on July 17th and 24th, found that average speeds on Prospect Park West have been reduced by nearly 25%, bringing five times as many drivers into compliance with the speed limit and cutting the number of vehicles traveling 40 miles per hour or faster by a whopping 95%.  The redesign, which narrowed the roadway from three travel lanes to two – replacing one travel lane with a parking-protected two-way bike lane, and adding wide refuge areas for pedestrians – was implemented in June by NYC DOT after calls for traffic calming from Brooklyn Community Board Six, Park Slope Neighbors, and the Park Slope Civic Council, among others.

Volunteers from Park Slope Neighbors conducted the speed survey as a follow-up to their March 2010 field survey, which was conducted prior to the redesign of Prospect Park West.  That study found that 85% of cars were exceeding the speed limit, and a startling 30% were averaging 40 mph or more.  The new results demonstrate a huge reduction in speeding – the primary goal of the Prospect Park West project.  A comparison of the pre- and post-redesign studies follows:

  March 2010 July 2010 % Change
Average Speed 36.6 mph 27.6 mph -24.7% (-9.0 mph)
Median Speed 37.0 mph 28.0 mph -24.3% (-9.0 mph)
30 mph or less* 14.7% 75.0% +409%
40 mph or above 29.9% 1.4% -95%
Sample Size 251 vehicles 352 vehicles  

    * The speed limit on Prospect Park West is 30 miles per hour.

"The speed-gun data shows without a doubt that the redesign of Prospect Park West has had a tremendous traffic-calming effect," said Eric McClure, campaign coordinator for Park Slope Neighbors.  "Prospect Park West has been transformed from a noisy speedway on which nearly every vehicle was speeding to a calmer, quieter neighborhood street on which the great majority of drivers are now obeying the speed limit.  What a difference a lane makes."

Speed is a major factor in all vehicle crashes, and has serious consequences in crashes involving pedestrians.  Studies have shown that a pedestrian has only about a 15% chance of survival when hit by a vehicle traveling at 40 mph; the survival rate jumps to 95% when speed is reduced to 20 mph.

In addition to achieving the goal of significantly reducing vehicle speeds on Prospect Park West, the redesign has shortened pedestrian crossings, gotten cyclists off the sidewalk by providing them with a safe, protected two-way bicycle path, and added an important and convenient link in the city's bicycle network.  The new bike path has already proven very popular with cyclists, especially young and novice riders who gravitate to the safety of a protected lane.

About the speed survey: the post-redesign speed survey was conducted with an accurately calibrated hand-held radar gun at Prospect Park West and Garfield Place, on July 17th and July 24th, in mid-afternoon, with a random sample of 352 vehicles.  The initial speed survey was conducted with an accurately calibrated hand-held radar gun at Prospect Park West and Garfield Place, on March 20th and 21st, 2010, in mid-afternoon, with a random sample of 251 vehicles.  The raw data is available upon request.

About Park Slope Neighbors: Park Slope Neighbors is a grassroots neighborhood organization dedicated to the protection and enhancement of quality of life in Park Slope, Brooklyn.

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