Efficiently Minimizing the Potential for Risk

20 May 2021 The Human Factor

Due to the physical and cognitive changes that come with age, senior citizens using the road find it harder to handle certain situations than they did when they were younger. Examples of such situations include changing lanes while over-taking, situations that are difficult to assess at junctions, turning maneuvers, conflicts on the road, and situations that require interaction with other road users. However, these drops in performance do not necessarily make senior citizens worse drivers; they can be compensated for in a number of ways, such as avoiding risky traffic situations and adopting a more defensive driving style. Specialized driving training courses and practical evaluations accompanied by experts can also help people to drive more safely.

People highly value having a driver’s license in our society – which is especially true for older drivers. It provides individual mobility in many areas of life, and is a symbol of vitality, independence and the joy of driving. Its importance to a person’s identity becomes particularly clear when an older driver’s license is revoked: they feel “robbed” of an important document, and sometimes like they are “not a complete person anymore.”
Studies have shown that even younger driv-ers tend to think of losing the right to drive as a traumatic experience – even more so than divorce, separation or unemployment. Typical negative consequences that older drivers can ex-perience after losing their driver’s license include symptoms of depression, and a deterioration in health and life satisfaction as a result of reduced social contact.
At the same time, the demographic shift rep-resents an enormous challenge to the transport community. In most OECD (Organisation for Economic Co-operation and Development) countries, such as the USA, Canada, Japan, Australia, France, Italy and Germany, senior citizens are the fastest growing demographic of the pop-ulation. According to the most recent UN population data, which was published in 2017, there will be more than 300 million people in the world aged 80 or over by 2040. By way of comparison, there were just 54 million in 1990, and 126 mil-lion in 2017. Likewise, senior citizens are the fastest growing group among driver’s license holders in all industrialized countries, including Germany. As life expectancy increases, more and more older drivers are using the roads.
The desire to provide lifelong mobility in order to help senior citizens remain independent, take active part in society, and enjoy a high quality of life is directly at odds with the fact that the number of traffic accidents caused by people aged over 65 has been rising steadily for the past 20 years, thus presenting politicians and safety experts with an almost insurmountable dilemma. In order to prevent the aforementioned negative impact of losing one’s driving license, older drivers need to be able to remain mobile for as long as possible and be assisted in this aim. At the same time, however, the government has a duty of care to the transport community in general, and cannot subject other road users to un-necessary and avoidable risks.
The key to devising effective road safety measures lies in reliably identifying which drivers can be presumed to represent a particularly high potential risk to all road users. A methodical approach to assessing this risk can be adopted by analyzing typical driver errors and causes of accidents, as well as typical age-related developments and changes in heath circumstances. This can provide us with important starting points for examination and consulting measures (enforcement/education) and networked design solutions (engineering).


As reported in the Accident Statistics chapter of this report, the official figures from the German Federal Statistical Office show that older people are involved with a high number of accidents relative to the short distances they travel compared to younger people. In addition to this, drivers aged 75 and over are often the main cause of road accidents in which they are involved. However, older drivers are more likely to use city roads and ordinary highways, on which accidents are more common, rather than freeways. They are also more susceptible to more serious injuries than younger or middle-aged road users when involved in the same kinds of accidents. Even minor injuries are more likely to be fatal for older people than for younger people, as the typical patterns of injury for the two age groups differ: for example, older people are more likely to suffer fractured hips or thoracic trauma.
Various studies have proven that complex road environments in particular can sometimes represent a huge challenge to older drivers. Such situations are made even more difficult when they involve junctions that are difficult to navigate or points where several different transport systems meet. This is also reflected in the results of extensive driving behavior surveys among older drivers, which indicate that navigating junctions and turning right and left are particularly dangerous situations for this demographic. It was also noted that senior citizens displayed unusual driving behavior when encountering cyclists and pedestrians, and tended to drive too fast when turning corners.


For Germany, the figures from the Federal Statistical Office paint a clear picture regarding accidents involving senior citizens as road users in 2019. According to these statistics, senior citizens were more frequently accused of ignoring rights of way when driving a car than under-65s (17.3 percent compared to 10.9 percent). “Making a turn, turning around, reversing, entering traffic, and driving off ” was the next category, with 16.7 percent compared to 11.9 percent. Among older pedestrians, the most common cause of accidents was “incorrect behavior when crossing the road” – at 78.5 percent; more than one in five of the older pedestrians included in the statistics had been accused of this. In almost two thirds of the cases (63.3 percent), the problem was “crossing the road without watching for traffic” (Figures 19 and 20).
There are a variety of possible reasons for making these kinds of mistakes when using the road, and in terms of preventability they range from “human errors,” due to being mentally overwhelmed for example, to “deliberate disregard for the rules.” The extent to which personal responsibility can be attributed for such situations can be determined more clearly by assessing the driver’s information processing abilities – e.g. their perception and their cognitive and motivational processes – in combination with their capacity to act appropriately, which includes their application of the regulations and their control of their vehicle. Even if an older driver accepts the rules of the road in principle, they may still find themselves overwhelmed by difficult situations on the road, which can lead them to tend toward unsafe driving behavior.
Experts attribute the main cause of mistakes made by older drivers to the deterioration in perormance that results from medical conditions and the biological aging process. The biological aging process affects everyone, regardless of any other medical conditions they may have, and is generally discussed in terms of cognitive and physical deficits. One aspect of the physical changes related to aging is a reduction in physical mobility; this manifests itself particularly as limitations in the ability to rotate one’s neck and upper body, which can lead to problems at junctions and when turning.


The cognitive changes associated with aging mainly take the form of deterioration in a person’s selective and divided attention, a decrease in the speed at which they process information, which in turn leads to slower reaction times, and the person requiring more time to carry out multiple activities. Age-related limitations in these cognitive processing resources affect the volume and complexity of information a person can handle at any one time, thus making the same driving task more strenuous for them to handle than it would be for a younger person. This, in turn, overloads older people more quickly in the form of tiredness and mental stress. This makes it harder for them to act according to the regulations and appropriately for the respective traffic situation, especially at complex junctions, at points with different rights of way, and when turning. This goes some way to explaining why older people are more prone to accidents, especially in these types of situations on the road. The ability to correctly judge speeds and distances also decreases with age.


In addition to the aforementioned normal changes that come with age, chronic illnesses also become more common as we get older. Examples of such conditions include cardiovascular diseases, diabetes mellitus and musculoskeletal conditions, all of which can impair a person’s suitability to drive even without the added complications of aging. In addition to this, an intact sense of perception and good vision (usually defined as at least 70 percent in both eyes) are particularly important for road safety, and thus to anyone who wants to be allowed to drive a car. After all, it is estimated that our eyes are responsible for recording 90 percent of all traffic-related information. The problem, however, is that vision deteriorates with age – on average, a 61-year-old will possess 74 percent of the visual acuity of a 20-year-old, and an 80-year-old just 47 percent. And because problems with mesopic vision tend to develop gradually over the course of many years, older drivers of-ten fail to notice them. Experts estimate that the mesopic vision of 22 percent of 60 to 69-year-olds and 34 percent of people aged 70 and over is impaired to such an extent that they are un-able to drive safely at night for this reason alone.
Like the visual senses, a person’s acoustic senses also deteriorate with age. The risk of hearing loss increases as a person gets older. This is problematic in terms of road safety, especially when combined with multisensory deficits (vision, sense of balance, dizziness in old age). Many older drivers have multiple chronic conditions, including those that affect their metabolism – for example, it is not uncommon for an overweight senior citizen with high blood pressure to also suffer from diabetes. People with all types of diabetes can experience severe drops in performance if they suffer pronounced complications, such as visual impairments or paralysis as a result of a stroke. Type-2 diabetes must be regarded as a risk factor for cardiovascular diseases. Certain types of diabetes can lead to secondary conditions that affect the eyes, kidneys, nerves, and the blood vessels in the heart, brain and legs, which in turn lead to functional limitations.
In a study on the health of older drivers and its effects on road safety, a systematic analysis of 400 case studies archived by the Driver’s License Office in Dresden, Germany, identified a number of risk factors found among drivers aged 65 and over who had displayed unusual driving behavior. The results of a government-prescribed driving suitability test were used to draw up a risk assessment. According to this, the probability of a negative result increased if the driver was older than 80, suffered from dementia or multimorbidity, or had been involved in a complex accident. However, individual conditions relating to eyesight, restrictions to movement, kidney conditions, diabetes or cardio-vascular disease did not increase this probability. This could be partly due to the fact that there are suitable strategies in place to help people manage such conditions, and that positive personality traits commonly found in older people, such as conscientiousness, presumably increase the probability of them complying with doctor-patient treatment programs. This means that it is not the diagnosis of a medical condition itself that characterizes a car driver, but rather how they deal with that diagnosis. Incidentally, Heart attacks at the wheel can have severe consequences both for the driver themselves and for all other road users the same also applies to temporary illnesses, regardless of how severe the symptoms are.


In addition to the typical deterioration in performance that comes with aging and limitations imposed by medical conditions, the effects of medication can also permanently reduce a person’s ability to drive safely. In Germany, the Drug Prescription Report (Arzneiverordnungsreport) for 2017 showed that every person with insurance over the age of 65 took 3.9 doses of different medications per day on average (for people over 80, the figure was even higher at 4.6), and that older patients were particularly at risk of suffering undesirable side-effects. At the same time, older people are particularly likely to be prescribed benzodiazepines and medications that, although beneficial for countering sleeping problems and alleviating anxiety and restlessness, also come with a significant risk of addiction. Taking benzodiazepines for an extended period of time can lead to general cognitive deficits that are not fully reversible. The undesirable effects of such medication are indisputably relevant to the issue of road safety, and range from tiredness, lethargy and drowsiness to conditions that affect psychomotor functions such as reaction time and concentration.
In addition to this, older people are at increased risk of developing conditions that cause chronic pain, such as diabetic polyneuropathy, osteoar-throsis and tumor diseases. These conditions are often treated using narcotic painkillers, which can generate undesirable side-effects similar to those listed above. Consuming alcohol in addition to such medication, even in small amounts, can ex-acerbate the problem further and lead to unpredictable results.
According to the results of a survey conducted several years ago, another medication-related issue is the fact that older men are particularly likely to underestimate the potential risks of taking medication on their ability to drive safely. In light of this, it would seem that we need to raise awareness of this problem in order to improve people’s self-control. This is a task that would be well-suited to general practitioners with the appropriate qualifications and training, for example.


Many older drivers are able to adapt their driving behavior to suit the deteriorating performance in their physical, cognitive and executive functions, particularly by implementing compensation strategies. There are two aspects to this. Firstly, the drivers in question start to avoid certain situations, such as driving in the dark, rush hour in towns and cities, busy roads, driving in poor weather conditions, and situations where the surroundings are difficult to assess. Secondly, they also reduce their speed in the respective situations, maintain greater distances to other vehicles for safety, and generally adopt a more defensive driving style. They may also use assistance systems to help them park and keep a safe distance to other vehicles.
However, there is still some question as to how realistic senior citizens are in judging their deteriorating performance, and thus to what extent they are able to consciously compensate for it. The literature contains contradictory results on this issue. While some experts claim that older drivers are good judges of their own abilities and behave responsibly, others believe that they do not see themselves as a risk factor, or that they consider themselves to be as good as or better than other drivers of the same age – what is known as the “better than average” effect. Such distortions of the way older drivers see themselves and judge their own abilities are likely one of the reasons why older drivers hardly ever give up driving voluntarily even when there are deficiencies in their performance. Instead, they refuse to reassess their mobility behavior until they experience a critical event – such as an accident, being stopped by the police, or taking a suitability test assessed by the driving license authorities.
Drivers who have multiple medical conditions or severe limitations with respect to performance, or suffer side-effects from medication or combination effects may find their options limited in terms of compensation strategies. In cases where limitations on performance due to medication or medical conditions are combined with deficits in the driver’s personality, such as a refusal to take the problem seriously or irresponsible behavior in response to information and advice provided by their doctor, the driver becomes a dangerous risk to road safety.