For example, a study by H. Wolfson published in 2011 found that when protected bike lanes are installed in New York City, injury crashes for all road users (drivers, pedestrians, and cyclists) typically drop by 40 percent and by more than 50 percent in some locations.
Street design dictates how fast people drive and how safe they feel. A wide, straight road invites speeding, regardless of the posted limit. Narrower lanes, tighter corners, and visual cues like trees and streetlights naturally slow traffic.