The act of driving a motor vehicle is a privilege and not a right, and driving is regulated by statutes in all 50 states in the United States and most countries around the world. Obtaining one’s license as a young adult is often considered to be a rite of passage toward independence. However, the loss of one’s license is associated with a loss of independence, especially in the elderly. The elderly, particularly in the United States, require mobility for many basic activities including doctor visits and grocery shopping.

Driving is a common activity in the United States, as highlighted in the most recent figures from the Federal Bureau of Transportation Statistics (5). Unfortunately, driving is also associated with morbidity and mortality from accidents. There were 42,643 motorists killed in the United States in 2003, with 2,889,000 people injured in 6,328,000 motor vehicle crashes during 2,880,000 million miles driven.

The ability to operate a motor vehicle safely depends on multiple factors and requires the operator to interact and react to multiple stimuli within the driving environment (9). These factors include traditional motor and sensory skills as well as a certain level of cognitive integrity. Most of the primary senses impact the ability to drive and are highlighted in Table 35-1.

As our population ages, the ability to drive and remain independent will likely gain more importance and scrutiny. It is estimated that, in 2000, 13% of the population was comprised of drivers over 65 years of age and accounted for 18% of all traffic fatalities (34). It is estimated that 60% to 95% of so-called excess fatalities in the elderly due to car crashes result from physical fragility (18). Car crashes can be life-changing events for the driver, passengers, and any victims. Car crashes involving medically impaired drivers and producing significant death and injury are often sensational in that they make “good copy” for the media (29,32). Reporting on these crashes or medical conditions in the popular press often introduces negative stigmatization of many medical conditions (7). Such reporting has consequences and can potentially influence public policy, opinion, and law. As a result of such recently reported crashes attributed to medical conditions, the Arizona legislature is considering whether to require physicians to report any patient who has a medical condition that could affect driving to a newly created medical review board for driving.

In the past, drivers less than 19 years of age were the most dangerous on the road. Young people crash at a higher rate for a number of reasons, with inexperience often cited as the most common reason (36). Although elderly drivers generally do not have issues of inexperience leading to car crashes, drivers over the age of 85 years have a higher crash rate than teenagers. Drivers past the age of 70 are particularly involved in certain types of crashes, including so-called angle, overtaking, and intersection crashes. The same older driver group is less involved in rear-end collisions (21). The reasons for this higher crash rate are many, but declining physical abilities are often cited to be a major contributor (22,25,37). Studies of elderly drivers with common medical and neurologic conditions often are limited by their design. Current studies of most drivers, the elderly included, are retrospective and uncontrolled in design.

The licensing process for private, noncommercial driving is generally codified by law in the individual states in the United States or countries in Europe. Driving restrictions related to various medical conditions are sometimes specifically mentioned in the law, whereas at other times, a more general restriction about any medical condition that could potentially impair driving is the standard. However, driving in persons with epilepsy (PWE) is specifically restricted in most jurisdictions (15). The restrictions are quite variable, with the seizure-free interval ranging from 3 to 12 months in the United States and the median
restriction being 6 months (15). The European Union has suggested a 12-month restriction in member nations with a 6-month restriction for a first time unprovoked seizure for private vehicle operators (11). For commercial drivers, the laws are much more restrictive, especially for those who drive interstate. The Federal Department of Transportation sets the regulations for interstate driving, which are generally administered and enforced by individual states. Consequently, the regulations for interstate commercial drivers are essentially uniform across the country. Intrastate driving is regulated by individual states, and laws governing driving are more variable.

Applying for a license requires an applicant to testify that he or she is medically fit to drive. Once a license is obtained, the renewal period is variable for private vehicle operators. An example of this is in Arizona, where the time period to renew one’s license can be more than 20 years (10). Much can change in this lengthy time period; operators are required to self-report any change in medical condition that may impair driving and undergo a medical review that determines one’s fitness to drive. The variability of state laws basically requires that the individual practitioner be familiar with individual state requirements where they practice.

Currently, there are six states that require medical practitioners to report a patient who has epilepsy to the driving authority (Table 35-2). Some states require reporting specifically for epilepsy, whereas others use the standard of altered consciousness. The American Academy of Neurology, American Epilepsy Society, and a recent European consensus conference all oppose mandatory physician reporting for epilepsy patients, citing an interference with the doctor-patient relationship (17). Patients will be reluctant to report a worsening of their medical condition to their physician if they know they will be reported to the authorities. Most states allow the health care provider to report the patient if necessary. California specifically requires the reporting of several other medical conditions that might impair driving, but epilepsy remains the most restricted medical condition when it comes to driving. A recent attempt to repeal mandatory reporting in California made it through the legislature and was vetoed by the governor.

Medical conditions account for a small percentage of all car crashes (9). The fatality rate for epilepsy-related crashes is higher than for other medical conditions (27), but the number of crashes related to epilepsy remains comparable to other medical conditions such as diabetes, heart disease, and even psychiatric conditions (9). If one groups alcohol-related crashes with “medically” related crashes, they account for about 40% of fatalities and about 7% of all crashes (9). One recent analysis of medically related auto accidents in Arizona showed that crashes related to epilepsy were more likely to be single-vehicle crashes (75%) with a trend toward more injuries when compared with other medically related crashes. All drivers had valid licenses to drive, and crashes occurred in both urban and rural settings. The average estimated speed at the time of the crash was lower than the posted limit, and weather was not found to be a factor in any of the crashes (9).