Why Speed Kills Cities - CityLab
U.S. cities are dropping urban speed limits in an effort to boost safety and lower crash rates. But the benefits of less-rapid urban mobility don't end there.
“Slow the hell down.” That’s the message New York City Mayor Bill De Blasio delivered on Twitter as he announced the revival of the city’s speed camera program. The cameras went live in July with expanded hours, issuing hefty tickets to any driver who creeps above 36 miles per hour—that’s 11 mph above the city’s 25 mph posted limit—in 750 school zones throughout the city’s five boroughs.
New York City, which has been struggling to get its Vision Zero safe-streets program back on track after a 2019 surge in cyclist deaths, has also been the most prominent American city to test the idea of a “neighborhood slow zone”—a relatively infrastructure-light path to safer streets that drops speed limits to 20 mph on interior roads in residential areas. It will soon be joined by Philadelphia, where the inaugural designation of two slow-speed corridors, modeled after the New York City program, was overwhelmed with more than two dozen applications.
Elsewhere in the U.S., urban speed limits are tumbling. Portland, Oregon, just wrapped up a campaign installing more than 2,000 new signs to bring residential streets down to 20 mph, along with educational “20 is plenty” signs. After lowering its default speed about two years ago to 25 mph, Boston wants to go further down to 20 mph; Washington, D.C., could follow suit. Imposing tighter limits on leadfoots is a key part of the Vision Zero campaign for reducing traffic deaths and injuries, because of the dramatic safety benefits associated with reducing vehicle velocity.
Does this add up to evidence that fast-paced Americans are ready to embrace the virtues of city life in the slow lane? The case for a fundamentally slower city has gained traction recently, especially in places where the rise of micromobility, the promise of autonomous vehicles, and the very-much-already-here problem of road congestion have converged, slowing drivers to a furious crawl. (The average car in Midtown Manhattan goes 4.7 miles per hour.)
Seeing cities scramble to accommodate shared electric scooters on conventional streets, Gabe Klein, the author of Start Up City, advocated for the idea of urban “slow lanes” in Forbes—non-separated but narrower travel lanes with a 15 mph speed limits that would prioritize non-cars. New York’s Financial District Neighborhood Association suggested the idea of creating an entire Euro-style “slow streets district” in a big chunk of Lower Manhattan, full of wide sidewalks and Dutch-style woonerfs, or shared streets. Others have suggested a wholesale woonerf-ization of the whole Manhattan street grid.