The bicycle in the focus of science

In conversation with Prof. Heather Kaths, Endowed Professor for "Planning Tools for Cycling of the Future" at the University of Wuppertal.

This is a good question, and not only in relation to Wuppertal. The situation for cyclists is not as good as it could be. What I do see, however, are many committed people who are interested in cycling and are working to improve conditions. Even compared to other cities that are a bit more advanced and where cycling is more important in everyday life, Wuppertal is not that bad. So if there was a better infrastructure, I could imagine that Wuppertal could quickly become a cycling city. I also see the basic causality, but with a little planning courage it would be possible to break it. Although it is of course clear that the conditions for this are much better in flat cities.

Yes, it's a great way to take the topography out of its defining function. Whether with pedelecs, electric bikes, e-bikes - even for older people who can no longer be active, hilly landscapes are no longer a problem factor. The only question is the charging possibilities. But even beyond electric mobility, there are very hilly cities where cycling plays a major role: San Francisco is a good example. In recent years, the city administration has taken the initiative to improve the situation for the cycling population, for example by closing part of the main traffic axis, Market Street, to private motorised traffic. Although a comparison with Copenhagen, for example, is not yet appropriate, the direction in which the city is moving is a start. And it also shows that the majority of cyclists can put up with a bit of an incline.

Both approaches would work. One point of contention in many places is parking, which is problematic in cities anyway: many cities do not want to remove or reallocate parking spaces because they want to avoid confrontation with residents or neighbouring businesses. The city needs the courage and self-confidence to say: "We can do without the parking spaces, we will find another solution. As soon as the space is free for cycle paths, the city is a big step further; and in the long term, the parking spaces may no longer be needed. It is different, of course, when busy streets are closed or reduced in size; this brings more hurdles and more protest, but has a great signalling effect for the whole spectrum of Active Mobility. The feeling in the city and its image to the outside world are greatly enhanced by such measures. So, as with so many things, a middle way promises the greatest success.

Exactly, that's what you always have to point out in discussions: The fear may be real, but the facts promise that there is no reason for it.

I don't see us scientists and myself specifically in the role of those who do the convincing, that comes much more in the form of independent initiatives from society. On the one hand, our task is to transfer a well-founded body of knowledge about the benefits that a high level of cycling activity can offer a city and how this can change the city for the better. On the other hand, and this is at least my main task, it is about providing municipalities with the appropriate planning tools they need to strengthen inner-city cycling. Which interventions are necessary at which point? How does the traffic flow at an intersection change due to the extension of a cycle path? How wide should a cycle path be, how should it be integrated into the rest of the infrastructure in order to be able to travel quickly and safely? My role is to answer these questions and to make sure that citizens can move around their city with a good feeling.

Many cities have already agreed to act as real laboratories to try out different infrastructure measures, such as traffic lights specifically designed for cycling. At the moment I am in contact with many cities and trying to find out where the needs are and what types of change are desired. I think that the micro- and macroscopic simulation tools that have been developed for car traffic can also be used for cycling planning - but it is optimal to develop your own ones that are adapted to the way cycling works, because in reality it is quite different and follows different patterns. So does pedestrian traffic, by the way. I am convinced that we can and should make use of the fact that everyone carries a smartphone with them today and generates data continuously to analyse behaviour on the bicycle. Because only when the current situation has been adequately explained can we think about the future in a practical way and consider: What does cycling need? And that is exactly where we should start. Once the behavioural patterns of cyclists have been sufficiently analysed, we can think about measures and recommendations for action. What is the interaction between cyclists like? What is the overtaking behaviour like? At what speed do people move, how dense are the flows? I will analyse this in detail and develop behavioural models that really reflect cycling.

You're right - that's what makes cycling so nice. You can adapt well and slowly roll through a traffic light with the foot traffic, then turn back onto the road and join the line with the car traffic, and thus make swift progress. To what extent one needs to limit this freedom remains to be seen - it is probably not the right approach to regulate too strictly. In my dissertation, I observed Munich's cycling traffic and found out that 80% of all cyclists do not stop when turning right, and in not a single case did this result in a dangerous situation. In the meantime, the green arrow has been introduced for cyclists, and experience with it has been predominantly good. It is certainly important to take this idea further. Incidentally, this is a point in which the Netherlands is very advanced: There, it is a matter of course that turning is made easier for cyclists.

On a bike, it is of course very nice when your own area is separated from motorised traffic and you don't have to worry about being hit from behind at any moment. Especially in North Rhine-Westphalia, many cities are showing the way, for example the cycle path through the Ruhr region. Copenhagen is - once again - a pioneer here. There, attempts are being made to create an independent network for cycling, at least where it is possible. On the other hand, the already existing infrastructure, the roads, can also be used by reducing the space for car traffic. At the moment, however, the trend is clearly towards the segregated network. What is often forgotten is that cyclists are not a homogeneous group that behaves identically.

A wide variety of people come together on a busy cycle path: those who want to go as fast as possible on their racing bikes, older people on city bikes, parents with their children on cargo bikes. Conflicts arise there too, because there is simply not enough space for everyone to ride at their own individual pace. As you can imagine: The overtaking manoeuvres are not always nice and patient, tensions and dangerous situations also arise. So how wide does the cycle path have to be in order to ensure a relaxed traffic flow with as little conflict as possible? In many places there are simply not enough cyclists to generate valid data on this.

Yes, with some. Many municipalities from North Rhine-Westphalia have volunteered to make their urban areas available as test sites. Slowly, a network is being built up, which is important not only for research, but also for the teaching course that I have planned and that will start in 2023. The students should have enough space to try things out for themselves and see how measures implemented on a trial basis, for example, translate into reality. But I am also exchanging ideas with municipalities in the Netherlands that are already a little further along than we are. Nevertheless, experience from other cities shows that a poor starting position does not necessarily mean less diversity of options. In cities with poor cycling infrastructure, there is a great drive among activists, which in many places leads to success.

In fact, the response I get is consistently positive. I had prepared myself for the fact that negative voices would certainly come complaining about the worsening conditions for car traffic, but so far that has not been the case. On the contrary, I have been contacted by people who say: "What you are doing is good, but more needs to be done in this or that area. The situation is very different from ten years ago, when I was told during my dissertation that prioritising cycling in Germany would be an extremely difficult undertaking. The feedback makes me very optimistic.

Thank you for the stimulating conversation and good luck with your research!