Is Bicycling Safe?

…would-be cyclists often ask: But is it safe? Will I have to pay for my environmental choice with crippling injuries or premature death?

Published September 9, 2007 by Raise the Hammer 
By Ryan McGreal

Raise the Hammer promotes cycling as a great transportation choice. It's cleaner and healthier than driving, producing zero emissions and achieving the equivalent of 595 km/l (1,400 mpg) in fuel economy.

Nevertheless, would-be cyclists often ask: But is it safe? Will I have to pay for my environmental choice with crippling injuries or premature death?

An article in View Magazine a couple of months ago advocated for better bicycle infrastructure by focusing on cycling dangers. Though well-intentioned, it reinforced many preconceptions without examining them for accuracy.

In fact, cycling is arguably safer than driving.

Comparing the Risks

Every activity carries risks, and are many possible ways to compare the relative risks of cycling and other activities. Looking at several can help to form a more complete picture.

Fatality by Distance Cycled

The most obvious comparison is the fatality risk per distanced traveled. In this straight-up analysis, cycling is more dangerous than driving. Every 1.6 million kilometres (one million kilometres) cycled produces 0.039 cyclist fatalities, compared to 0.016 fatalities for motorists. They're both very low, but the risk for cycling is more than double.

However, this is not the most useful way to compare risks.

Fatality by Time Spent Cycling

Failure Analysis Associates, Inc. performed a comparative analysis of fatality rates for a variety of activities per million hours spent performing a given activity. They concluded that the fatality rate for every million hours spent cycling is 0.26, compared to 0.47 per million driving hours (on-road motorcycling comes in at a whopping 8.80 deaths per million motorcycling hours).

That is, riding a motor vehicle has nearly twice the risk of fatality as riding a bike for a given duration.

Overall Fatality and Commute Homeostasis

According to the US National Safety Council, for every million cyclists in the US, 16.5 die each year, whereas for every million motorists, 19.9 die each year.

This is important, because it helps us to draw conclusions about how the higher risk per distance traveled interacts with the lower risk per time spent traveling. Cycling is more dangerous on a straight distance comparison, but because drivers travel farther on average, the overall risk to an individual is higher for drivers than for cyclists.

This is related to what we might call "commute homeostasis", or the amount of time a person is willing to spend traveling. All things being equal, a person is willing to travel a farther distance only if they can get there faster.

People who drive tend to live farther away from destinations (e.g. work commute) than people who cycle. In fact, one benefit of cycling is that it saves so much money that cyclists can often afford to live much closer to where they work.

Cycling also tends to place a premium on proximity, so cyclists are more likely to locate in places where many destinations are nearby, which reduces the cycling distance and hence the risk as a function of distance.

Fatality Rate in Crashes

Another way of evaluating risk is to examine the odds of dying if you do crash. Common sense dictates that crashing in a bicycle has a higher risk of death than crashing in a motor vehicle, but according to the NHTSA, bicycles compare rather well.

The odds of dying from a bicycle crash are one in 71. This compares to one in 75 for a light truck (pickup truck, SUV, van), one in 108 for a car, one in 43 for a truck, one in 26 for a motorcycle, and one in 15 for a pedestrian.

In other words, the odds of dying in a bike crash are about the same as the odds of dying in an SUV crash. The false sense of security that comes from an SUV tends to produce far more dangerous driving behaviour.

"Life Years" Gained and Lost

In addition to the direct risk of death or injury, cycling and driving also carry indirect risks that must be factored into account.

According to a study by the British Medical Association, the average gain in "life years" through improved fitness from cycling exceeds the average loss in "life years" through cycling fatalities by a factor of 20 to 1.

Driving confers no commensurate health benefits through improved fitness; in fact, time spent driving actually correlates with poorer overall health and higher risk of heart disease, obesity, diabetes, cancer, and related lifestyle diseases.

Psychologically, it's hard to weigh the slight risk of being hit by a car tomorrow against the vastly reduced risk of having a heart attack in twenty years, but it is far too significant to ignore.

Risk is Mutable

Since cyclists are not a homogeneous bunch, it makes sense to examine whether and how cycling behaviour affects fatality rates. It turns out that cyclists who ignore the rules are much more likely to die than cyclists who follow the rules.

The difference is so stark that it would make more sense to regard them as two separate populations for the sake of comparison. Averaging the two groups – cyclists who follow or who disregard the law – together obscures the vast differences in their relative risks.

It also obscures the fact that an individual cyclist's choices strongly influence their risk of fatality. Cyclists are not helpless victims of safety statistics (even encouraging statistics).

It might not be politically expedient to state, but in the majority of bicycle crashes, the cyclist is at least partly at fault. Cyclists are hit when they ride on the sidewalk and appear out of nowhere at intersections; when they pass on the right; when they ride at night without lights and reflectors; when they ride the wrong way down one way streets; when they ride too closly to parked cars; and so on.

Bike infrastructure can certainly help: streets with clearly marked, well-maintained bike lanes are safer than streets without them. It's also clear that bike lanes increase the perception of safety for would-be cyclists.

However, the way you ride is a bigger factor in accident prevention. The absolute best way to avoid accidents is to ride as though you are driving a motor vehicle. In other words: be visible, follow the rules of the road, pay close attention to what's happening around you, and practice defensive riding. You will earn the respect of motorists, maximize your safety, and get the most enjoyment from cycling.