Protected Bike Lanes Cut Injuries by 40%—But U.S. Cities Are Still Debating Them
New infrastructure data shows separated bike lanes make roads safer for everyone, yet opposition and equity concerns complicate rollout.
Every year, hundreds of cyclists die in traffic crashes in the United States. The reasons are depressingly consistent: high-speed roads, inattentive drivers, and infrastructure designed for cars first, bikes never. But there's a solution that works—and the data is overwhelming.
New York City's injury rates for all road users, including drivers, pedestrians, and cyclists, typically decreased by 40 to 50 percent in areas where the city implemented protected bike lanes. That's not a rounding error. That's a public health intervention on par with seatbelts.
What Protected Infrastructure Actually Means
Traditional bike infrastructure, often in the form of bike lanes and shared lanes called "sharrows," fails to protect cyclists by requiring them to share the road with cars, while protected infrastructure offers cyclists safety from cars through separation in the right-of-way via off-street trails, buffered bike lanes, and cycle tracks.
Think physical barriers: plastic bollards, curbs, parked cars, or even planters. The goal is to eliminate the scenario where a driver drifts into the bike lane—whether from distraction, aggression, or simple misjudgment—and hits a rider.
A higher availability of bicycling infrastructure is associated with better safety outcomes for bicyclists and other road users, especially when bike facilities are protected and separated, with protected bike lanes appearing to reduce bicyclist injuries, increase cyclists' perception of safety, and reduce bicyclist crashes, especially when tall, continuous barriers or a grade with horizontal separation are used.
The Evidence From Around the World
In Montreal, streets with protected bike lanes had 28 percent lower injury rates than other streets, on average. A University of Colorado Denver and University of New Mexico study found that cities with protected bike lanes had 44% fewer deaths for all road users. That last point is critical: safer bike infrastructure doesn't just protect cyclists. It slows down cars, reduces severe crashes involving pedestrians, and creates calmer streets overall.
Creating safer bike lanes has already been shown to decrease New York City's cycling injuries by 32 percent, and by introducing additional separate bike lanes on streets, the risk of cycling accidents could drop by another 30 percent.
Why the Pushback?
If the data is so clear, why aren't protected bike lanes everywhere? Two words: parking and perception.
Despite the benefits of protected bike infrastructure, opposition is common, often because such improvements require cities to remove parking, but those views are typically in the minority, and ultimately removing parking spots and replacing them with biking infrastructure benefits community health, promotes safety, and provides economic benefits to businesses.
The economic argument is backed by data. In 2013, Salt Lake City converted nine blocks of parking to a protected bike lane, and sales rose 8.8 percent for stores located along the bike lane—compared with a 7.0 percent increase citywide. Bike-accessible neighborhoods see more foot traffic, longer dwell times, and repeat visits from customers who arrive on two wheels.
The Equity Question
There's a darker side to the debate. Research suggests that bicycle lane investments are typically made in areas of greater sociodemographic advantage. That pattern has led to concerns about bike infrastructure as a vector for gentrification—wealthier, whiter neighborhoods get safe lanes, then property values rise, then longtime residents are priced out.
To ensure cycling projects benefit everyone, cities should work to promote equity of access in planning projects by prioritizing investments in communities with more residents of color and families with low incomes, and projects should be constructed with existing residents at the forefront of decisionmaking about routes and improvements.
What Good Design Looks Like
On streets with high speeds (of over 30 km/h) and where up to 6,000 vehicles travel each day, cyclists need to be protected from passing cars with a well-marked and dedicated space, and temporary elements such as visible paint, reflective plastic cones, freestanding barriers, and light-duty bollards should be placed between the bike lane and the vehicle lane, with these bike lanes being "one-way" only and following the same direction of car traffic to avoid risk of collision.
In general, a bike lane should measure 2.2 meters minimum—enabling two cyclists to ride side by side comfortably. Where speeds exceed 50 km/h or traffic volumes top 6,000 vehicles per day, bike lanes must be protected from car traffic with heavy-duty physical separators—such as curbs, bumpers, bollards or barriers.
Lowering speed limits on city streets through simple design changes and speed-calming measures could help prevent or reduce injuries. Vision Zero planning—the goal of eliminating all traffic deaths—recognizes that human beings make mistakes, and infrastructure should be forgiving when they do.
What This Means for Your Riding
If you commute or ride in urban areas, get involved. Show up to city council meetings, submit comments on transportation plans, and support advocacy groups pushing for protected infrastructure. In partnership with the Department of Transportation, state and local agencies, community groups and individuals have a significant role in determining how safe the transportation network in their community will be, and state and local transportation agencies and MPOs, who plan, design, build, and maintain roads, are required by law to improve the safety of transportation infrastructure, including for vulnerable road users like pedestrians and bicyclists.
When you ride, use protected lanes when available, but don't assume they're fail-safe. Intersections are where most urban cycling crashes occur, and mastering intersection technique dramatically reduces your risk. Watch for right hooks, take the lane before turns, and never assume a driver sees you.
The infrastructure debate isn't abstract. It's about whether people feel safe enough to ride a bike to work, to school, to the grocery store. The data says protected lanes work. Now it's on cities—and voters—to build them.