In New York’s slow zones, speed humps are the only physical traffic calming measure. London uses a greater variety of traffic calming measures, installed more intensively.
New York’s quick and cheap approach to creating “neighborhood slow zones” isn’t working, according to a new paper from Columbia University graduate researcher Jonas Hagen.
NYC DOT launched its slow zone program in 2011, inspired by a similar effort in London to create 20 mph zones. There are now 28 slow zones across the five boroughs, each encompassing an average of 25 city blocks.
While the program generated enthusiasm from neighborhood groups and created a template for residents to organize for and opt into DOT traffic-calming efforts, the implementation wasn’t robust enough to reduce fatalities and injuries, Hagen concludes. But the London program, which included more physical street design changes, led to a measurable reduction in severe traffic collisions.