On an Island where risk is the stock-in-trade of large companies, I offer up the following definition cautiously: Risk is the probability of something bad happening.Risk is part of our everyday lives. In fact risk can, in a sense, be viewed as the spice of life; a life completely devoid of it would be a boring one indeed. Realistically, it’s virtually impossible to live a risk-free life and so what it comes down to is finding a way to manage the risks in our daily lives. The first step to managing the risks in our lives is to quantify them and here, it seems, is where the problem starts.Turns out we have a very hard time evaluating risk accurately. We are hard-wired to assume the worst as a matter of survival. Our ancestors rarely dismissed the rustle in the brush because to do so might result in becoming a predator’s lunch. Unfortunately, this hard-wiring remains incomplete (in the frontal lobes of our brains) until early adulthood. This inability to accurately gage risk leads to both unnecessary anxiety in some instances and tragedy in others. Basic information about the risks we face or think we face in our daily lives can help put some perspective on what we should or should not worry about.Now there’s more to risk than the simple probability or likelihood that something bad will happen. Equally important is the consequence. An infrequent event such as a nuclear reactor meltdown poses a risk because of the shear severity of its consequence. Furthermore, for a risk to exist, there must be a hazard. The risk of shark bite in Ohio does not exist because that hazard is not present. Finally, the definition of risk must take into account exposure. If you live on a hilltop, your exposure to floods is low.So, here’s a more accurate way of defining risk: Risk is the probability that exposure to a hazard will lead to a negative consequence. With this definition in mind, let’s have a look at the risks of driving while impaired (DUI).DUI combines two important hazards, alcohol and driving/riding a vehicle. The hazard posed by driving a car or riding a motorcycle has been well studied and we know that the vast majority of road fatalities in Bermuda occur with the latter. Riding a motorcycle is dangerous. How dangerous?Per vehicle mile travelled, a motorcyclist’s risk of a fatal crash is 35 times greater than a passenger car occupant and the rate of serious injuries is 16 times greater. One of the reasons motorcyclists are killed so often in crashes is that compared to car occupants, the motorcycle itself provides virtually no protection in a crash; approximately 80 percent of reported motorcycle crashes result in injury or death compared to 20 percent for automobiles.Alcohol is a central nervous system depressant. At very low blood alcohol concentration (BAC), one begins to experience some loss of judgment as well as a decline in visual function and the ability to multitask. At the maximum legally permissible BAC of 0.08 percent, one experiences a decline in muscle coordination, balance, speech, vision and reaction time. Driving is affected as concentration, speed control and information processing are impaired. At twice the maximum permissible BAC, there is significant loss of muscle control and balance resulting in substantial impairment of vehicle control, attention and visual and auditory information processing. As you might have guessed, BAC increases the risk of crash.Now, what can we expect when one is exposed to both these hazards simultaneously? The US National Highway Traffic Safety Administration (NHTSA) has published figures for the relative risk of fatal crash involvement by BAC, age and gender and the numbers are sobering ... pardon the pun. (NHTSA’s study looked only at single vehicle crashes in order to eliminate shared driver fault.)Overall, young drivers experienced higher relative risks of single vehicle crashes than did older drivers of the same sex. Additionally, female drivers exhibited substantially lower relative risk than male drivers of the same age perhaps because they are more cautious drivers.Alarmingly, the study estimated that each 0.02 percentage point increase in the BAC of a driver with a non-zero BAC more than doubled the risk of receiving a fatal injury in a single vehicle crash among male drivers 16-20. The table below illustrates the relative risk of fatal single vehicle crash among three age groups of males for different BACs:BACAge (males) 0 .050 — .079 .150+16 — 20 Relative Risk 1.0 17.32 15,585.8521 — 34 Relative Risk 1.0 6.53 572.5535+ Relative Risk 1.0 5.79 381.68The table shows quite clearly that even at BACs just below the legal level, 16 — 20 year olds are over 17 times more likely to be in a fatal single vehicle crash. At approximately twice the legal BAC, the relative risk increases to more than 15,000 times compared to a sober driver. Although not as dramatic, the increased relative risks for older drivers is worrisome.In a country with few effective deterrents to drinking and driving, it is no wonder that we top the charts for road fatalities. Furthermore, while it might be understandable that your average road user fails to accurately gage the risks of impaired driving, it is absolutely inexcusable that our elected officials stand idle while the problem has been addressed so effectively in other countries. Well publicised and strategically placed sobriety checkpoints and mandatory alcohol/drug testing of all drivers/riders involved in road crashes are interventions with a proven track record, as politically unpalatable as they may be.* The views and opinions expressed herein are solely those of the author and do not necessarily reflect CADA’S position.