Human Error is the Biggest Risk Factor

08 Nov 2020 The Human Factor

As we have already seen from the facts and figures listed in the Accident Statistics section, human error among road users – particularly users of motorized and non-motorized two-wheeled vehicles – is a huge risk factor.

As we have already seen from the facts and figures listed in the Accident Statistics section, human error among road users – particularly users of motorized and non-motorized two-wheeled vehicles – is a huge risk factor. For example, according to the German Federal Statistical Office’s figures for 2018, “incorrect use of the road” was by far the most common cause of accidents for cyclists in Germany, accounting for almost 12,500 accidents resulting in personal injury, while the figures for both motorcyclists and users of motorcycles with insurance tags (light motorcycles, small mopeds, pedelecs, threewheeled motor vehicles, and light fourwheeled motor vehicles) were dominated by a “failure to adjust speed” (accounting for around 6,600 and almost 1,700 accidents resulting in personal damage, respectively). Other common forms of human error include driving under the influence of alcohol, a failure to observe rights of way, risky overtaking maneuvers, and mistakes made when making a turn, turning around, reversing, entering trafic and setting off.
In this context, it is also interesting to look at the Allianz Center for Technology’s calculations on the main causes of accidents that resulted in personal injury in Germany by type of road user from 1991 to 2018. These figures show that the number of accidents that were caused primarily by a cyclist has risen by almost 30 percent in the specified time period – from almost 33,000 in 1991 to around 42,550 in 2018. Especially since 2013, the increase in this percentage has been constant and occasionally dramatic – however, it is also important to not that the absolute number of cyclists on the road and the total mileage have also been continuously on the rise during this period. Over the same period of time, there has been an almost 25 percent drop in the number of accidents resulting in personal injury that were caused primarily by drivers of cars, falling from around 273,500 to approximately 206,000.



Motorcyclist, cyclist, pedelec rider, or user of a scooter or e-scooter – for every one of these groups, interaction and communication with other road users are key factors in their safety, and sometimes even their survival. This is especially true when it comes to ensuring an understanding between users of two-wheeled vehicles and motorists. Research results on this subject indicate that there are a wide range of communication patterns, some of which increase road safety while others are more likely to escalate the situation. The latter effect is particularly common when emotional factors such as anger and rage come to the fore. The fact is, as the acceptance and presence of bicycles as an everyday mode of transport increases, people who used to prefer driving are now more commonly choosing to cycle instead. The mode of transport a person chooses often depends on the situation, with factors such as the distance and quality of the route and the current trafic situation coming into play. When someone changes their mode of transport, this inevitably also alters their perception and the way they assess situations on the road. This change in individual perspective can help to teach both drivers and cyclists safer patterns of interaction with one another.


In this context, it is particularly interesting to look at the results of a study commissioned by Ford in 2018 as part of its “Share the Road” campaign. The study showed that using different modes of transport affects a person’s perception. Around 2,000 people from Germany, France, Italy, Spain, and the United Kingdom were asked to recognize and distinguish between pictures under laboratory conditions. The results showed that motorists who also rode bicycles demonstrated better situational awareness. In 100 percent of the scenarios they were shown, these test subjects were quicker at identifying the pictures and spotting the differences between two pictures.
According to a study by Rowden, P. et. al. (2016), it can be generally assumed that many drivers are more likely to adhere to the regulations when traveling by car than when riding a bicycle. One reason for this may be that they see themselves as less of a danger when cycling than they would when driving a car, and thus perceive their nonobservance of the regulations as being less serious. Schleinitz, K. et al. (2016) collected data from reallife situations for a study comparing the natural riding styles of riders of different classes of bicycle (bicycles and pedelecs). The participants in the study used their own bicycles, which were fitted with measuring equipment and cameras. Among other things, the report analyzed situations where cyclists breached the regulations, for example by ignoring a red light.


The results showed that the cyclists breached regulations in order to avoid stopping at a red light in more than 20 percent of situations, though this figure varied significantly depending on the type of bicycle. Common approaches included riding straight through the red light without stopping, and stopping briefly before crossing while the light was still red. In particular, red lights were ignored with above-average frequency when turning right at a junction. Running red lights was particularly common at T-junctions, which shows that cyclists are more willing to breach regulations in situations that are easy to assess. When asked why they had breached the rules, the participants were particularly likely to respond that they wanted to maintain their speed, or also to make their journey shorter.
In addition to the running of red lights, improper use of infrastructure was also common. Cyclists and pedelec riders often rode on sidewalks illegally. Due to the large number of breaches, it seems sensible to strive for closer monitoring and stricter punishment of cyclists, though other measures such as corrective training should also be part of the solution. In all cases, punishment for conductrelated offenses should always include an inspection of the vehicle to ensure that it complies with the legal regulations and is road safe.


One of the biggest risks to road safety are the conflicts in communication that can develop between cyclists and motorists. These arise primarily as a result of behavior that the other group of road users perceives as inappropriate, or even aggressive. For example, aggressive behavior on the part of cyclists is often a response to cars performing driving maneuvers the cyclist views as dangerous, and vice versa. Cyclists also often see cars parking in bicycle paths, overtaking too close to bicycles, and opening car doors without due care as deliberate provocation.
Generally speaking, many motorists see cyclists as an “outgroup” (Walker et al. (2007)) who do not belong on the road. The dismissive or even aggressive attitude displayed by such drivers is the consequence of the perception of cyclists as “interlopers” and the resulting emotional stress. This perception is more common in countries with a poorly developed bicycle infrastructure and where cyclists make up a smaller percentage of the total trafic. Cyclists and motorists display different reactions to stressful situations: Cyclists tend to avoid open conflict, whereas motorists react more confrontationally. This should also be interpreted as a result of the differences in the two groups’ subjective senses of safety.
A study by Heesch, K. C. (2011) tackles cyclists’ experiences with harassment and bullying by motorists. An online survey conducted by Bicycle Queensland, an organization that promotes bike use, received 1,830 responses. In total, 76 percent of the men and 72 percent of the women who responded reported that they had experienced harassment or bullying by motorists on the roads in the past twelve months. The most common forms of such behavior included overtaking too close to the cyclist (66 percent), verbal abuse (63 percent) and sexual harassment (45 percent). The probability of a cyclist being subjected to such behavior is dependent on factors such as age, body weight, cycling experience/frequency, and the location of the journey. Young to middle-aged cyclists with more experience on the road seem to be more likely to be affected by this than older cyclists. According to the aforementioned survey, the same applies to both cyclists who cycle competitively and purely for fun, and also to those cycling in more well-off areas.
The fear of such harassment is a barrier to people who would like to cycle but do not yet do so. One way of counteracting this problem would be evolutionary perspective, the tendency to look at a person’s face during a social interaction can be explained by the fact that the appearance and facial expressions a person makes can provide their opposite number with a lot of information on their intentions and characteristics. However, the presence of indicators such as a person’s face and the direction in which they were looking when a motorist was required to interact with cyclists or other vulnerable road users often distracted the motorist and extended their reaction time. Yet since focusing on the face is not a reflex, it is a tendency that can be lessened through training and awareness-raising measures.


A study by Walker, I. et al. (2007) showed that motorists usually direct their gaze to a cyclist’s face when they come into contact with them. While gestures made by the cyclists, such as an outstretched arm indicating that they want to turn off at a junction, help drivers to deduce the cyclist’s intentions and the direction in which they intend to ride next, it is the cyclist’s face that the driver looks at first and for longest. This trend was true irrespective of the gender and experience of the test subject, and became more pronounced when the cyclist seemed to be looking at the test subject. These results indicate that social cognitions are triggered during interaction with cyclists. From an evolutionary perspective, the tendency to look at a person’s face during a social interaction can be explained by the fact that the appearance and facial expressions a person makes can provide their opposite number with a lot of information on their intentions and characteristics. However, the presence of indicators such as a person’s face and the direction in which they were looking when a motorist was required to interact with cyclists or other vulnerable road users often distracted the motorist and extended their reaction time. Yet since focusing on the face is not a rflex, it is a tendency that can be lessened through training and awareness-raising measures.
In situations where the cyclist offered no clear formal information such as hand signals, the motorists paid more attention to the bicycle itself. Earlier studies have shown that motorists are also highly capable of determining a cyclist’s intentions based on their position on the road. Since many of the channels of communication employed by cyclists are informal and thus not clear, young cyclists in particular should be provided with more information on potential communication problems – such as the fact that motorists often do not see their signals and cannot predict what they are going to do. Public information campaigns tailored to safety education among all groups of road users and their interaction should emphasize cooperative and considerate conduct on the road, and teach that all road users have the same rights to the use of public space.


Walker and his research colleagues indicated a few other factors that affect the behavior of road users. The study shows that a cyclist’s position on the road, the type of bicycle they are riding, whether or not they are wearing a helmet, and their gender all have an impact on how motorists overtake them, as motorists ascribe different character traits to the cyclist based on these indicators. The further away from the curb a cyclist is riding, the less space a motorist will give them. In summary, the research showed that motorists give cyclists less space if they are wearing a helmet, cycling in the middle of the road, and are male, and also if the motorist in question is a bus or truck driver. This indicates that these motorists usually follow a certain course when overtaking, on which the position of the cyclist has only minimal effect. However, it is not necessarily safer for cyclists to ride closer to the side of the road, as this may put them at risk due to other factors, such as sewer grates and parked vehicles. In particular, it is less safe for cyclists to stay close to the side of the road at junctions, as motorists mainly focus on the area around the middle of the road when watching for trafic, which makes it easy for them not to notice cyclists.
The ending that cyclists are afforded less space when wearing a helmet indicates that they are seen as safer and more protected against severe injury in case of an accident. As a result, motorists see it as less dangerous to overtake a cyclist wearing a helmet than one who is not. Motorists overtook at a greater distance when they perceived the cyclist to be female, possibly because they judged female cyclists to be more unpredictable or more easily susceptible to injury. It is true that each of these studies focuses on a specific region, and that driving styles are dependent on a number of factors which can vary from region to region. Nevertheless, it is clear from these points that motorists adapt their overtaking behavior based on the characteristics they perceive a cyclist to possess, and that they do not have an impartial overtaking pattern that they apply to all cyclists as a group.


In addition to the characteristics of the cyclist, the type of vehicle overtaking the cyclist also played a role. Buses and heavy goods vehicles were the types of vehicle that overtook significantly more closely to the cyclist. This is probably due to the fact that these vehicles require more time to complete an overtaking maneuver due to their dimensions and slow acceleration, and that they also need to pull further into the other lane than other vehicles in order to overtake. Since long gaps in oncoming trafic are rarer, these vehicles overtake closer to the cyclist. In addition to this, there is also a risk that drivers of larger vehicles may not be able to see a cyclist at all times during an overtaking maneuver, which leads to them pulling back into their lane earlier even though the cyclist is still riding alongside their vehicle. This example demonstrates particularly clearly that separate bicycle paths are essential to increasing cyclist safety.
In their study, Horswill, M. S. et al. (2015) tackle in more detail the interplay between driving style and technology and infrastructure. Generally speaking, extending the cycleway network reduces the number of accidents that occur in terms of mileage. When the cycle infrastructure enables safe separation of cyclists from fast motorized traffic, this improves cyclist safety. This effect is particularly noticeable at junctions, though on the other hand, infrastructural separation has proven particularly difficult in such areas. In turn, increased safety results in a higher number of cyclists. Alongside changes to cycle infrastructure, measures that make it easier to clearly assess the trafic on a road so that vulnerable road users such as pedestrians and cyclists are not overlooked as easily are also useful. Driver assistance functions in the motor vehicle that make it easier for drivers to notice cyclists and pedestrians could also help with this. Despite the fact that cyclists are not generally permitted to ride on the sidewalk – at least not in Germany – measures such as restrictions and prohibitions on parking on sidewalks, together with stricter sanctions for those who disregard such regulations, would also be effective in increasing the visibility of users of twowheeled vehicles.
Hamilton-Baillie, B. et al (2008) also tackle the issue of communication behaviors between different groups of road users, and present the concept of a “shared space”. This concept aims to integrate road users in a single place without impairing safety, mobility, or accessibility. In particular, it aims to improve road safety through mutual consideration of others. Communication between road users plays the key role here and is the top priority, as all road users have equal rights. The features of this model include the principle of mixing all road users together and thus doing away with most signs and restrictions, as all road users would follow implicit rules. This principle is by no means new, and has in fact been practiced in a range of towns and cities for several decades. Positive examples of the application of this concept include the Laweiplein junction in Drachten (Netherlands) and Blackett Street in Newcastle (England).
Typical design techniques for shared spaces include keeping the all parts of the space the same height so that pedestrians and users of motor vehicles and non-motorized vehicles all interact on the same level and the space feels like a single, self-contained area, and subtle markings that identify the different areas. The removal of most of the signs and traffic lights promotes organic communication and reduces speeds. Shared space usually results in a successful restructuring of the way a road is used: There are fewer traffic jams, and the lower speeds mean that there are fewer accidents and that the consequences of said accidents are less severe. There is also evidence that shared spaces increase the satisfaction levels of all road users. However, traffic planners should always thoroughly assess whether it makes sense to implement a shared space in a specific location before doing so.