Cycling Safety Positive Feedback Loop

Assuming cyclists have “safety in numbers,” the real question I posed in my last post is how can St. Paul or Minneapolis (or Anyplace, Minnesota) get more people on bikes?

The best way spur cycling is to make cycling appear safer. This recipe has many ingredients, but the most critical is giving users what they perceive as important: better protection from cars.

Is bicycle only infrastructure a golden ticket to such? Not necessarily. A burgeoning research base is forming around this issue (see, for example, exemplary studies[1],[2],[3]), however, to date it fails to provide divine inspiration. Advocates are quick to focus attention on ‘hot-spot’ maps depicting the number of crashes. Or they quickly dig out the most recent study showing how a new facility on a street lowered crash rates. But how well do these examples stack up to the balance of the literature? More than a few robust studies show bike facilities contribute to crashes.

The literature on cycling safety is vast, complicated to sort, and context dependent. The analysis of the 2,973 bicyclist-motorist crashes in Minneapolis found that bicycle crashes are complex and lack a single contributing factor. Likewise, studies relating crashes to facilities are often shaky on three accounts:

(1) Evidence relies on crashes as outcomes and fails to capture near-misses or other safety indicators. Bicycle crashes with cars are an infrequent occurrence among an infrequent activity. Even less is known about bicycle-only crashes (with stationary objects), crashes with other pedestrians or bicyclists or “looked but did not see” type interactions; municipalities don’t collect this data.

(2) Measuring and comparing cycling treatments varies by context—by culture, by type of facility, and by its location in the network. Despite accepted terminology[4], a “protected bicycle lane” differs from the next. Knowing how a studied facility fits into other network issues is similarly troubling.

(3) Any study needs to control for the number of cyclists at risk (i.e., exposure). Lacking a robust accounting of this dimension, a study is all but useless from the perspective of explaining safety risk[5].

Other issues always get in the way. Were speeds controlled? Was bicycle education routinely provided? How well did the study control for the experience of cyclists, socio-demographics, season or time of day factors? Addressing confounding explanations is a challenge that exists in all fields. However in cycling studies the challenge is heightened. Bicycle crashes are usually secondary data, confounders are often unavailable, and proxies are unclear. Furthermore, bicycle crashes involve pain, injury, and sometimes death. Cyclists don’t want to hear, “it depends”; they prefer straightforward and positive results.

But the best we know is that bicycle facilities (e.g. on-road bike routes, on-road marked bike lanes, and off-road bike paths) in some places appears to help reduce the risk of crashes, relative to cycling on the road with motorized traffic road[6]. This statement has caveats that are embedded in the context. Facility quality and context are paramount in understanding how people behave and who uses it.

Given this unstable landscape, what is the strongest rationale to get more people on bikes and increase safety? The best line of reason is derived from our basic instincts as humans: a longing for safe environs. In his hierarchy of basic human needs[7], the sociologist Maslow placed safety just after physiological needs (e.g., breathing, food, and water). Safety desires influence behavior; most people at least perceive places with good cycling facilities to be safer.

It is easy to turn to hoards of anecdotes and personal observations: “It’s too dangerous on that street; there’s no bike path,” or “I’ll never bike there; the cars drive too fast and too close.” Such ‘anecdata’ are less than satisfying. These desires, however, are reflected in robust surveys of cyclists’ preferences, all of which point in the same direction: (1) safety features can be used as motivators to bike[8],[9],[10] and (2) existing cyclists prefer to ride where there are facilities[11],[12],[13]. People routinely report feeling safer with various types of facilities; generally, they want more separation from traffic rather than less[14]. Perception is reality and perceptions usually correspond well with observed behavior[15].

If residents perceive their cycling to be safer, they are more likely to bicycle and bicycle more often, which has the added benefit of increased safety through safety in numbers. Given this tautological reasoning, good bicycle facilities are the intervening element to initiate the “cycling safety positive feedback loop.”

[Thanks much to Meghan Winters, Krista Nordback, and Rebecca Sanders who provided valuable insights, guidance, and recommendations; any errors interpreting the balance of the literature are of course mine]