Bike lanes painted in the door zone of parked cars cause 20% of all urban cycling crashes

In most U.S. cities, conventional bike lanes are painted directly adjacent to parked cars, placing cyclists squarely in the "door zone" — the 3-to-4-foot arc where a car door swings open. When a driver or passenger opens their door without checking for cyclists, the cyclist either slams into the door at speed or swerves into moving traffic to avoid it. This is called "dooring." Dooring accounts for 19.7% of all reported bicycle crashes in Florida, 16% in Santa Barbara, and 5% in Boston, with over 800 dooring incidents reported annually in New York City alone. In February 2024, a 64-year-old Citi Bike rider was killed on Broadway near Lorimer Street in Williamsburg when a driver opened a car door into his path, sending him into traffic where a second vehicle struck him. At least 24 cyclists have been confirmed killed by dooring nationwide, though the real number is almost certainly far higher because most dooring crashes go unreported or are miscategorized in police reports. The reason this persists is that door-zone bike lanes are cheap. Painting a stripe on existing asphalt costs a city roughly $5,000-$15,000 per mile, while a physically protected lane costs $100,000-$500,000 per mile. Cities count these painted lines toward their "miles of bike infrastructure" metrics for federal grants and political credit, even though the design itself creates the hazard. The AASHTO guide has recommended a minimum 5-foot buffer between parked cars and bike lanes since 2012, but most cities grandfather in existing designs because retrofitting would require removing parking spaces — which triggers fierce political opposition from merchants and residents. So the painted line stays, and cyclists keep getting doored. Structurally, the root cause is that bike lane design standards are advisory, not mandatory. There is no federal requirement that bike lanes be built outside the door zone. Cities can and do build door-zone lanes and still receive federal transportation funding. Until funding is conditional on meeting minimum safety geometry, the cheapest design will keep winning.