Driver errors

High Risk of Accidents Caused by People’s Behavior

Aug 12, 2021

Violating another vehicle’s right of way, failing to adjust your speed, driving too close to the vehicle in front, driving under the influence of alcohol, being distracted by smartphones or other electronic communication systems: These are just some of the ways in which the ‘human factor’, i.e. people’s own behavior, plays a major role in road accidents. “Across Europe, almost 90 percent of accidents are caused by human error,” reports Markus Egelhaaf, accident researcher at DEKRA. Young drivers and senior citizens are particularly affected by this issue. As shown in DEKRA’s Road Safety Report 2021 entitled “Old-Age Mobility”, driver errors by the 65+ demographic are often caused by their restricted physical movement and by their slower reactions.

  • Young drivers and senior citizens are particular risk groups
  • Complex traffic situations are often challenging for older people
  • DEKRA Road Safety Report 2021 puts “Old-Age Mobility” in the spotlight
Human error has been by far the most common cause of road accidents for many years. According to figures for 2019 from the German Federal Statistical Office, 88.2 percent of accidents resulting in personal injury in Germany were caused by driver error, while 3.2 percent were caused by pedestrian error. Just under 65 percent of errors were attributable to car drivers. Vehicle technology and road infrastructure can play a role in either preventing high-risk situations from occurring in the first place or mitigating their consequences. “However, it’s the drivers themselves who can play the biggest part in improving road safety – by acting responsibly, correctly assessing their own abilities, and closely following the rules of the road,” says Markus Egelhaaf, accident researcher at DEKRA.
If we look at how many car drivers from a given age group were involved in accidents resulting in physical injury and compare this with the number of accidents caused by that age group, it becomes clear that young novice drivers and senior citizens are particular risk groups. There are clear differences between these two age groups when it comes to the types of driver error that caused an accident. While 18 to 24-year-olds predominantly failed to adjust their speed correctly and keep a safe distance from the vehicle in front, by far the most common mistake made by the 65+ demographic was violating another vehicle’s right of way. This was followed by mistakes when turning and with keeping a safe distance from the vehicle in front. Up to the age of 65, men are much more likely than women to cause an accident due to driver error. After the age of 65, this difference levels out.
Deterioration in performance can lead to mistakes when driving
If we look at the accidents caused by car drivers’ errors, we see that the ability to handle complex traffic situations plays an increasing role as we move up the age groups. This is particularly true when it comes to violations of rights of way in out-of-town areas and on freeways. In 2019, for example, these accounted for less than ten percent of accidents in the 18-to-24 demographic but rose to just under 25 percent by the time we reach the 75+ demographic. The opposite trend can be observed for accidents caused by a failure to adjust the speed. This error caused around 30 percent of accidents in the 18-to-24 demographic but dropped to approx. 10 percent in the 75+ demographic. In built-up areas, too, driver errors made in complex traffic situations also become a major factor as drivers get older. Moreover, we can see a clear increase in the number of driver errors made against cyclists and pedestrians in built-up areas. In contrast, this only plays a very minor role overall in non-built-up areas, which reflects the fact that these two groups spend less time exposed to other road users in such locations.
“These data show that complex traffic situations need to be the primary starting point when devising measures for safer mobility for older car drivers,” highlights Markus Egelhaaf. In addition to infrastructure optimization, in-vehicle assistance systems can also help with this issue. Ultimately, however, many accidents caused by violations of rights of way, that occur when turning, or that involve cyclists or pedestrians, are linked to physical or health-related limitations among the senior citizens responsible for the accidents.
Age-related factors
For example, as people become older their physical movement becomes more difficult, which causes problems with looking over their shoulder, turning their head quickly, or changing where they are looking. Overall, they also have slower reactions, which is often exacerbated by the influence of medication. As our bodies age, we cannot process the same amount or complexity of information as before. When driving, this can lead to issues such as tiredness or mental stress more quickly. The ability to correctly judge speeds and distances also decreases. However, it is precisely these abilities that are required in complex traffic situations, such as at confusing intersections, when turning, or when encountering cyclists or pedestrians.
If we want to create a world of safer mobility, including for older drivers, we need to focus more intensively on using a range of strategies to improve infrastructure and vehicle technology, but above all to improve how people themselves behave. Specific recommendations for achieving this goal can be found in the DEKRA Road Safety Report 2021 entitled “Old-Age Mobility.” It can be found at