Subjective safety in bicycle traffic
Road safety is often assessed on the basis of accident figures recorded by the police. Quantitative surveys only reflect a part of the problem. Unrecorded accidents, near missed ones and, in particular, subjective perceptions of safety are factors that influence traffic behaviour and the choice of means of transport. Our understanding of the perception during cycling, however, is comparatively low.
Subjectively safe in this context means "that cyclists consider the probability of an accident to be sufficiently low" [Hagemeister 2013]. On the basis of this definition, cycling seems rather unsafe, and 47 percent of cyclists consider it as a rather unsafe or very unsafe means of transport in terms of accident risk [BMVI 2017].
People choose the means of transport that best meets their needs. If the bicycle is to become the first choice of everyday means of transport, it is indispensable for the future promotion of cycling to increase both objective and subjective safety when cycling.
This concern is also shared by large sections of the population, who are currently active in an increasing number of cities and are joining forces to push “Bicycle Referendums” in order to promote cycling. The current discussion focusses on the safety aspect in cycling. In many cases, the allocation of more space for cycle traffic (regarding “fairness in space allocation” [Text in German] of the different means of transport) is one of the basic prerequisites for achieving this goal.
Different types of cyclists and perceptions
It is difficult to measure how different types of cyclists and target groups perceive and assess their own mobility. Everyday, habitual and occasional cyclists share the same traffic safety requirements, but differ in their traffic flow requirements (e.g. with regard to speed or the design of junctions). In order to categorise people according to cycling types, initial scientific approaches divide cyclists into three categories based on their driving skills and age. Accordingly, there are cyclists in group A with very good abilities who can also move well on main roads and in mixed traffic. In group B there are cyclists with average abilities who require separation from roads with high motor vehicle speeds. Those with low abilities (including children and cyclists with lower than average knowledge) are in group C [Merkuria et al. 2012].
More recent approaches not only consider the abilities and sociodemographic characteristics of cyclists, but also assess their stress tolerance in road traffic in order to assign them to four classic user types (target groups) and derive targeted measures from them. The assessment of the cycling infrastructure is therefore based on the stress it causes among its users.
The classification of Roger Geller, bicycle traffic officer of the city of Portland, is a pioneering step in this direction. He divided cyclists into the four types "fearless", "habitual cyclists", "interested" and "non-cyclists". Geller's typology has since been scientifically confirmed and further developed by several studies at Portland State University. Accordingly, 2/3 of the population can be classified as habitual (enthusiastic and self-confident) and interested (interested but worried), and thus form the core target group of cycling promotion [Geller 2009].
The fact that the typology of the "Four Types of Cyclists" is also likely to apply to Germany, has become apparent in the results of two largest surveys on cycling in Germany, the bicycle monitor and the ADFC bicycle climate test.
In Germany, the majority of respondents would also like to ride a bicycle, but many of them does not feel safe enough in road traffic. This is particularly the case on busy roads, where cyclists have to ride on a street - nevertheless if a cycle lane is marked or not. According to studies, even experienced everyday cyclists would prefer to drive separately from motor traffic [BMVI 2017; ADFC 2018].
For 70 percent of respondents to the Bicycle Monitor 2017, unseparated cycle paths are a source of insecurity. Other factors that cause discomfort include too much traffic (71 percent) and ruthless car drivers (65 percent) [BMVI 2017].
Together with the "Silicon Valley Bike Coalition", Google developed the so-called „Google Bike Vision Plan“, which will provide Santa Clara County (situated north of the Silicon Valley) with a network of cycle paths in the next few years that everyone between the ages of 8 and 80 can cycle along safely and comfortably. In order to be able to subjectively evaluate the cycling infrastructure, Google measures the stress of cyclists when they use the various routes and displays this on maps.
Positive feelings are important, but objective safety is essential. If the cycling infrastructure requires increased attention by its users, this does not necessarily have to be dangerous. Increased attention to the changed situation may well benefit individual safety under certain circumstances.
In order to create a low-stress and subjectively safe infrastructure, it is important to identify the situations that cause stress to cyclists. An "emotional map" (so-called "emotional mapping") may help planners.
In the „Urban Emotions“ project by the Karlsruhe Institute of Technology (KIT) and the University of Salzburg, researchers assessed stress situations to which cyclists were exposed to while riding (“Urban Emotions” is a follow-up project to "EmoCycling" from 2013). In the experiment, cyclists receive a smart band, a GPS tracker and are equipped with an action camera that additionally records the situations from an ego perspective. The smart band measures the data of the skin (temperature and skin conductance), which can then be assigned to emotions such as stress. The data is then synchronized and visualized on a map. Different colours show where cyclists often experience stress. In addition, the test persons can use a push button during their ride to mark stress situations.
The aim of the study is to evaluate to what extent the two methods - automatic stress measurement vs. survey through marking of stress situations while cycling - provide relevant recommendations for the design of individual traffic facilities. A comparison of the two methods shows that their results confirm each other and at the same time supplement each other with relevant information. While the data provided by the test persons on the marked stress points provide important information on the actual perception of the cyclists, the automatic stress measurement documents situations which are not taken into account in the test persons' data for various reasons. The results of the study underline the potential of research approaches that compare subjective data and objective conditions in the infrastructure.
Subjective safety in rules and regulations
The term "subjective safety" is not mentioned separately in Germany's "Guidelines for Urban Road Design (RASt, 2006)" but the terms "social security" and "social control" are taken up.
Germany's "Recommendations for Cycling Facilities (ERA, 2010)” describe in particular areas of application, safe forms of bikeway design on the route and in the particularly critical areas at crossings and junctions. It should therefore be noted that all road users are able to clearly recognise cycle traffic infrastructure and that visual relationships between cyclists and other road users must not be disturbed. In addition, the interests of children for safe participation in traffic should always be taken into account [FGSV 2010 ].
Another quality feature of Germany's "Recommendations for Cycling Facilities (ERA, 2010)” at network level is a "socially safe" infrastructure, which should be clear and visible and provide "social control" or the supply of appropriate alternative conditions (e.g. at night) [ibid].
Furthermore, the design requirements dealing with road safety aspects explicitly recommend to avoid situations in which cyclists feel vulnerable or overwhelmed. The bikeway design should be chosen in such a way that the dependence on the behaviour of others is low. In this context, infrastructural design under the principle of forgivingness (passive safety) is often mentioned [ibid: 15].
The Germany's "Recommendations for Cycling Facilities (ERA, 2010)” identify different forms of cycling infrastructure, but leaves open which one should be implemented for which target group. This decision is up to the traffic planners, who take their decisions on the basis of local conditions and given priorities.
Design of bikeways: Different bikeway types
The design of cycling infrastructures is determined by the acknowledged regulations and recommendations. In principle, with the exception of the two way cycle tracks in urban areas, the typical forms of bikeway design types are considered objectively safe (in accordance with ERA 2010) if correctly designed [BASt 2016].
Cycle tracks (separation of car traffic)
Cycle tracks at the side of the road guarantee a safe cycle traffic, both subjectively and objectively, provided that the safety and quality standards are adhered to. In the case of cycle tracks, junctions and property access roads are the most significant hazards. It is therefore crucial in planning to ensure that the visual relationships between road users are maintained at all times.
The subjective sense of safety of many cyclists supports the decision for bikeways separated from car traffic. Especially older and inexperienced cyclists feel threatened by the proximity to a faster car.
Experts warn of the dangers, even though the cycle paths separated from motor traffic are preferred for reasons of subjective safety. The perception of safety can be deceiving, as the problems and risks (blind spots, etc.) on decades-old cycle tracks are often not sufficiently taken into account.
Advisory, mandatory and protected cycle lanes
In Germany, cycling traffic is often shifted to the road. This often reduces the feeling of safety. Germany’s current bicycle monitor shows that 81 percent of cyclists consider it "very important or important" to be on a road seperated from car traffic [ADFC 2019]. Many cyclists feel more comfortable on cycle paths, where they are clearly separated from car traffic. For this increased feeling of safety, they also accept worse cycle paths would even make a detour.
With regard to subjective and objective safety, advisory and mandatory cycling lines were controversially discussed. A current study by the German Insurers Accident Research (GDV) [cf. https://nationaler-radverkehrsplan.de/de/aktuell/nachrichten/udv-publikationen-zur-sicherheit-von, text only in German] examines the road safety of these design types and makes it clear that many cyclists do not feel safe on the marked lines. In the study, it was observed on both types of cycle lanes that cyclists are hindered by parked cars when riding on the cycle lane (40 or 10 percent). A further danger is that the necessary safety distances of overtaking cars are often not maintained. No form of link has a significant effect on normal overtaking operations. On both cycle lane types side distances are often less than 1.50 m, so many cyclists avoid narrow lanes in particular and switch to sidewalks. In addition, high accident densities were recorded at very narrow cycle lanes [GDV 2019].
According to Ohm et al., cycle lanes increase the acceptance of road use by cyclists and lead them to switch from the sidewalk to the carriageway. However, they also noticed an increase in accident density on the road and a tendency towards smaller overtaking distances [Ohm et al. 2015].
Based on the investigations of the GDV it is recommended to increase the safety distances to stationary traffic at the edge of the road and to the flowing traffic on the vehicle lanes and thus to positively influence both the objective safety situation on the cycle lanes and the subjective perception of the cyclists. Furthermore it is said: "If it is not possible to mark sufficient widths and a bikeway on the side of the road is not possible, mixed traffic - possibly also in combination with the reduction of the permissible maximum speed - has to be considered" [GDV 2019].
A further option is the installation of Protected Bike Lanes. The study by Monsere et al. 2014 shows that Protected Bike Lanes lead to significant increases in the volume of bicycle traffic compared to previously existing mixed traffic solutions. The respondents stated that because of the Protected Bike Lanes they generally choose their bicycle more frequently as their preferred means of transport.
The survey also showed that the choice of vertical separation measures (e.g. bollards or flower pots) is only of secondary importance. Although measures with greater separation got better rates, each vertical measure led to a significantly more positive perception of the bicycle lane compared to a mere marking [GDV 2019].
Roads with priority for cyclists (cycle-only roads, bicycle boulevards)
The survey of road users on roads with priority for cyclists has shown that overall knowledge of the rules of conduct applicable here is insufficient. However, 70 per cent of the road users surveyed still find it a safe form of bikeway design for cyclists. The respondents cited the aspects "parking vehicles" and "speed of vehicles" as risks [GDV 2016].
According to the Copenhagenize Bicycle-friendly Cities Index 2017, Copenhagen ranks first in the world-ranking of bicycle-friendly cities - also because people feel extremely safe cycling there.
Copenhagen pursues a clear strategy in network planning. Cycle tracks run along main roads throughout the city, making them the most important network element. The cycle tracks are separated from the road by kerbs seven to nine centimetres high and from the sidewalk by kerbs five to nine centimetres high. At intersections there are extra blue marked bicycle lanes.
This way, cyclists are physically separated from the rest of the traffic and are not tempted to use lanes other than the comfortable, wide, tarred cycle paths. On the one hand the Copenhagen planners rate this variant as the safest form of bikeway design, on the other hand it is also best accepted by the population [Graf 2016].
In Copenhagen, cyclists are sometimes guided by separate cycle lanes to the right-hand lane of motor traffic in order to increase the attention of all road users.
- The signposting for cycling should be continuous, consistent, informative and easily legible from a distance.
- Cycling lanes on the road should always be sufficiently wide, if possible well beyond the minimum dimension and also beyond the standard dimension [GDV 2019].
- If possible, vehicle traffic should be reduced in very narrow streets (e.g. implementing one-way streets for cars or disabling stationary traffic).
- If possible, separation markings between cycle lanes and stationary traffic should be marked and sufficiently wide in dimension.
- The combination of minimum dimensions or the use of narrow cycle lanes on roads with heavy traffic should be avoided. Instead, bicycle traffic should possibly be part of mixed traffic and permitted maximum speed should be (effectively) reduced.
- In addition to the infrastructural design, non-compliant behaviour should be adequatly sanctioned to ensure safety for all road users.
Subjective impressions are important with regard to the design of cities, but are often not taken into account in the planning due to the lack of a methodology for recording them, as quantifying instruments are largely lacking. In order to significantly increase the quantity of everyday bicycle traffic, human sensations, habits and perceptions must be given greater focus from the planning point of view.
Classifying cyclists into user groups with their mobility needs, special infrastructure requirements and individual potential can be helpful in finding target group-oriented measures. A first step can be to make infrastructure for cyclists as objective and subjective safe and "stress-free" as possible. To achieve this, sufficient space must be made available and, at the same time, a redistribution of space in favour of cycling must be considered. Without sufficient space, neither an objectively nor a subjectively safe design can be guaranteed.
The design of the bikeway type plays a decisive role concerning the sense of safety of cyclists. With regard to objective and subjective safety, it is advisable to always consider the respective spatial situation and the local conditions in context to the suitable bikeway type.
In order to ensure that cycling does not require bold courage, municipalities should take people's subjective feelings seriously and strengthen them. Suitable survey and evaluation methods must be applied which help to include the perception of safety in the planning, especially in addition to the statistically recorded accident blackspots.