This text on older drivers reviews the scientific studies on the magnitude and nature of the safety problem, the contributing accident factors, and the effectiveness of countermeasures.
Diagram & Summary
Who is at risk
Older drivers are not so much a risk to others, but they are at risk themselves. This means that older drivers are not a risk to others' transport safety, but they are frailer, making them vulnerable to personal injury or fatality risk in the event of a crash. As a result, older drivers have a relatively high fatality rate, but their injury rate is much lower. Data from the Netherlands illustrates this.Taking the distances travelled into account, the fatality rate for car drivers is more than 5 times higher for those aged 75 years and over than for the average for all ages, whereas their injury rate is two times higher. The conclusion that the older driver is not a danger should not lead to a limitation of the development of road safety measures targeting older drivers. Nor can the claim be made that all drivers are sufficiently safe to continue driving. It depends on the physical and mental condition of the individual. Information on the crash types of older drivers should be taken into account when designing safety countermeasures. Older drivers are over-represented in crashes occurring while turning off at intersections, where typically the older driver turns against oncoming traffic with right of way on the main road. Older drivers are "under-represented" in crashes involving loss of control or collisions due to speeding, risky overtaking or driving under the influence of alcohol.
Functional limitations and physical vulnerability
The road safety of older road users is to a large extent determined by two factors: functional limitations and physical vulnerability. Both factors contribute to the relatively high fatality rate for older road users as a result of crashes. Functional limitations can increase crash risk, whereas a higher physical vulnerability increases injury severity. A third reason for the high fatality rate of older adults seems to be their low annual mileage. In general, drivers travelling fewer kilometres have increased crash rates per kilometre compared to those driving more kilometres. These three explanations for the high fatality rate for older drivers are most probably connected, with the physical and mental condition of the driver having the biggest influence on the other two factors. Drivers who have a medical condition are also likely to be more fragile than other (older) drivers and will also drive less frequently or at least drive shorter distances.
As people age - a process that does not start at the same age for each and every individual - functional limitations and disorders occur which may increase the crash rate of road users. This is particularly the case in the decline of motor functions like muscle strength, finely tuned coordination, and the ability to adapt to sudden changes in bodily position. There are few indications that a decline in visual and cognitive functions, as part of normal ageing, also has road safety consequences. Only in the case of severe sensory, perceptual, and cognitive limitations does the relation between functional limitations and crash involvement become visible. Examples are eye disorders such as cataract, macular degeneration, and glaucoma, and diseases like dementia, stroke, and diabetes.
Functional limitations and age related disorders do not automatically lead to unsafe traffic behaviour. Other characteristics of older road users can prevent safety problems. Among these are the insight into one's own limitations, driving experience, and compensation behaviour such as driving when the roads are less busy or when it is daytime and dry.
If, in spite of behavioural compensation, a crash occurs, the older driver is more vulnerable than younger drivers: his injuries will be more severe given an identical collision impact.
Factors that will influence future developments
Various factors can contribute to an increase or reduction of the current number of fatalities among older drivers. These factors can be divided into autonomous factors and road safety measures. Examples of autonomous factors are the age composition of the population, the number of older adult driving licence holders, their mobility, and their driving experience. If these factors change in the course of time, they will influence the future number of fatalities among older drivers.
Increases of the number of people aged 75 years and above, of the driving licence rates for older people and of the mobility per older driver will increase the future number of fatalities among older drivers. The latter increase will, however, be toned down by reduced fatality rates due to future older drivers being more vital and experienced than those of today. Road safety measures can further reduce the fatality rate of older drivers in the future. Examples of measures are described in the next section.
Different types of measures available to change the future
Several types of measures are available to influence the future number of fatalities among older drivers. Taking into account the causes of the high fatality rate among older drivers, a set of measures which is aimed at reducing the fatality rate of older adults should at least include measures that are aimed at reducing injury severity, such as improvements of active and passive vehicle safety. Measures that can reduce the crash involvement of older adults also contribute to a reduction of their fatality rate. Examples of such measures are providing education and training, infrastructural adaptations, and driver assistance systems. In the case of a progressive decline of functions, training and adaptations of the infrastructure and the vehicle can no longer compensate for reduced fitness to drive. Therefore, in addition, a procedure is needed that will lead to a timely cessation of the driving career. Possible measures are licensing procedures and consultation of doctors.
Safety versus mobility and quality of life
A test procedure which results in people losing their driving licence when they can still drive a car safely is undesirable for a variety of reasons. First of all, the fatality rate for older cyclists and pedestrians is many times larger than that for older car drivers. Consequently, they are safer in a car. In addition, older people often have already stopped cycling, partly because of loss of balance. Saying farewell to their car often is also a farewell to part of their social lives. As a result, the loss of driving privileges can cause considerable distress and a lowering of self-esteem and dignity, as well as create difficulties for daily activities, shopping and social contact.
The availability of means of transport other than the car is one of the most important ways to maintain older people's mobility. However, no single form of transport provides mobility for all people under all circumstances. Therefore, a family of services is needed that enables travellers to select the one that best suits their requirements for a particular journey. These services include: public transport services, bus service routes, taxis, Dial-a-Ride service, and an accessible pedestrian infrastructure for journeys on foot or by wheelchair or scooter.