Driving safety involves factors related to the vehicle, the roadways, the weather and other conditions. Above all, driving safety involves the driver. This chapter focuses primarily on drivers and on determining their fi tness for driving. Although it is important to ensure that a vehicle is in proper mechanical condition, that issue is beyond the scope of this book. I'm working from the assumption that the vehicle is in good working condition. Also, other factors play a role in how safely a person can operate a vehicle: the conditions of the roads and a driver's familiarity with them, the weather, and the time of day all can affect driving safety. Obviously, all possible conditions can't be addressed here, but they should be taken into account when determining driver fi tness. If you are concerned about a driver's fi tness, you will want to observe his or her driving fi rsthand and keep a written record of your concerns. The forms in Appendix 1 should help you.
Driving Fitness and Age
At the most basic level, driving requires that we have the ability to properly see, think, and move. Limitations in any of these three key functions may signal a worrisome threat to driving fi tness. Illness, age, and even signifi cant life events can all impair your ability to see, think, and move. Signifi cant life events, such as the loss of a spouse, may be so distressing that they contribute to physical changes that, in turn, affect driver safety. For example, the physical symptoms of fatigue and slowed thinking are common in grief. While these symptoms are perfectly normal, they can impair your ability to drive safely. See Chapter 2 for more information about common age-related changes and medical conditions that may impair driving fi tness.
Contrary to what many people believe, age, by itself, does not determine driving fi tness. What matters in driving are three fundamental functions: the ability to see, think, and move. These abilities change at different rates for different people. Some people in their 90s and beyond are more healthy and fi t for driving than some people in their 50s or 60s. Thomas Perls, M.D., M.P.H., a professor at the Boston University School of Medicine, became interested in this phenomenon when he noticed that some of his oldest patients were some of his healthiest. Dr. Perls directs the New England Centenarian Study and is widely regarded as one of the world's leading experts studying adults aged 100 years or older. His research shows that centenarians age relatively slowly, and seem to have delayed or entirely escaped diseases associated with aging such as heart disease, stroke, cancer, and Alzheimer's disease.