Small steps useful in reducing risk
Humans are notoriously poor at internalizing abstract risks. We tend to regard flying as inherently riskier than driving though we know we’re far more likely to die in a traffic accident than in an airplane crash. An evolutionary bias against abstract risks causes us to ignore simple steps that would improve our odds.
Two doctors at the Sunnybrook Health Sciences Centre in Toronto have produced some calculations that suggest a slight decrease in average driving speed on our streets and highways would dramatically cut the number of vehicle accidents and their associated costs in property damage and human injury and death.
In a study published in the Journal of Medical Decision Making, they estimate that just a three kilometre per hour reduction in average vehicles speeds would result in about 9,000 fewer deaths annually from U.S. traffic accidents. The United States has about 15 times more traffic deaths than Canada.
In an attempt to bring the highway risk and safety message closer to the individual, the study authors calculate that every hour of driving decreases one’s life expectancy by 20 minutes – a rather alarming ratio, when you think about it. In fact, it’s about double a common figure stated for smoking: 11 minutes of life expectancy lost for every cigarette smoked.
Even personalizing the statistics like this probably doesn’t in itself prompt any changes in behaviour, though the minutes-per-cigarette projection could be useful as a psychological motivator for someone trying to quit.
The other problem with statistics is that we understand intuitively that these are averages applied across populations. We all know someone who lived a healthy lifestyle and contracted cancer at an early age; conversely, we all know someone who burned the candle at both ends but lived into old age. Psychologically, we seem to be predisposed to optimism, figuring individually that we’re in the percentile that won’t have to pay for indulgences and risky behaviours.
Rational response to risk projections therefore requires a combination of individual and collective action. As individuals we can quit smoking, but we can also make laws and programs to encourage this behaviour across the population. Similarly, a persuasive case can be made for laws and policies aimed at reducing vehicle speeds for two main reasons: safety and fuel conservation – the latter offering the bonus of reduced greenhouse gas emissions. Vehicle fuel efficiency decreases dramatically above 100 km/h, yet not only do we spend billions building highways to enable high legal speeds but we then we fail to enforce the posted limits.
Big problems call for big solutions but for starters we could be picking the low-hanging fruit like a moderate decrease in driving speeds.