Want More Bike Commuters? Build Protected Bike Lanes, Says New Study

For decades, planners and advocates, and those communicating with baseball players of the past, have repeated the mantra: “Build it, and they will come.” But another new study, this one just published in Nature Cities on June 2, refines that phrase with the kind of data-driven insight cycling advocates love: “Build the right kind of infrastructure, and more people will ride.”

The six-year study by Nicholas N. Ferenchak and Wesley E. Marshall examined more than 14,000 urban block groups in 28 U.S. cities, comparing changes in cycling commuting rates against the installation of various types of bicycle infrastructure. The headline result is striking: protected bike lanes (PBLs) were far more effective at boosting ridership than standard lanes, sharrows or doing nothing at all.

For those working to normalize cycling in car-centric cities, this is more than academic. It’s evidence of what works—and what doesn’t—at street level.

Protected Bike Lanes Trump Paint

The study’s big takeaway is simple and clear: not all bike infrastructure is created equal. The difference in performance between types of facilities is dramatic.

Block groups that added protected bike lanes saw commuter ridership increases 1.8 times higher than those that added standard bike lanes (SBLs, yes, paint), and 4.3 times higher than those that added no infrastructure at all. Buffered bike lanes (BBLs) performed slightly better than SBLs, but the clear champion in the data was the protected lane.

While sharrows (shared-lane markings) are still treated by some cities as a low-cost option to check a box on cycling improvements, their efficacy was marginal and a waste of time. Once socioeconomic and built environment factors were accounted for, sharrows offered zero significant relationship with ridership growth.

In other words, paint alone doesn’t protect riders—and it doesn’t attract them either, which any bike commuter of more than a week experience would know.

The Longitudinal Advantage

According to those behind the study, previous research often relied on cross-sectional snapshots, which made it hard to determine causality. Did new infrastructure cause more cycling, or did cities with more cyclists get better infrastructure?

Ferenchak and Marshall’s use of six years of longitudinal data and multiple statistical models helps answer that question more definitively. Their work supports a causal link: installing protected bike lanes leads to more people commuting by bike—especially in cities that previously had little infrastructure.

Even when PBLs were installed in neighborhoods with already-high levels of cycling, they still yielded significant additional growth, demonstrating their appeal to both seasoned riders and newcomers.

Protected bike lane on
Penn Avenue in the Cultural District, Pittsburgh

Stress Levels Matter

Cyclists—and potential cyclists—don’t just need infrastructure. They need the right kind of infrastructure.

The researchers categorized infrastructure by “traffic stress,” a framework that’s gained traction in recent years. Protected bike lanes and buffered lanes rank as low-stress, whereas standard lanes and sharrows are high-stress facilities, often placing riders adjacent to fast-moving traffic with little or no separation.

Standard bike lanes might serve a confident minority, but protected lanes attract the majority who might otherwise be more cautious —the riders who might want to cycle but won’t do so unless they feel safe.

Beyond just what cities built, the study also looked at how much. When researchers analyzed the effect of infrastructure mileage on ridership growth, the results were again striking.

The conclusion is crystal clear for planners: if you want a real return on your investment in cycling infrastructure, protected lanes offer the best bang for the buck.

Beyond the Numbers

As cities work to meet climate goals, reduce congestion, and promote equity in transportation, bike commuting presents a low-cost, high-impact solution. But encouraging that shift doesn’t come from marketing campaigns alone—it comes from building infrastructure that feels safe.

The research validates the growing emphasis on “low-stress networks” being adopted by cities like Portland, Austin, and Montreal.

This study gives those efforts a solid, evidence-backed foundation—and a powerful message for holdouts: if you’re still investing in sharrows, you’re wasting money.

What Comes Next

While this research is groundbreaking, it also opens doors to future study. What kinds of protection—flex posts, curbs, planters—work best? Do protected lanes on high-speed arterials perform differently than on quiet collectors? How do these investments affect ridership among women, older adults, or children?

And perhaps most critically: how does the connectivity of a network influence its success? A single protected lane is useful—but a citywide grid of safe routes is transformative.

Final Thoughts on Protected Bike Lanes

The cycling community has long known what this study confirms with facts: if you build safe, protected infrastructure, people will ride.

So yes, build it—but make it protected, connected, and low-stress. That’s how we get more people on bikes.