Population growth and urbanisation are making for ever-busier cities. “All these people have to go to work, school, shop, go out and visit family and friends. That is putting huge pressure on the mobility system, creating challenges in areas such as traffic flow, safety, health and liveability,” says Bart van Arem, professor of Transport Modelling. “Several of the larger municipalities are already taking anticipatory measures, such as limiting car access to certain city zones. Research has shown that this leads to better air quality and a nicer environment for locals.”

Radical change to the mobility system

Although Van Arem is in favour of local mobility initiatives, a more radical transition is needed to solve the problems. “To relieve the pressure on public space and to clean up our mobility footprint, we need to move towards more shared transport and fewer private cars, more electric and self-driving vehicles, including small ones such as the Light Electric Vehicles (LEVs). That means a complete overhaul of what we have been used to so far. Instead of having our own car parked in front of the house, we will have a shared car parked perhaps somewhere down the road.”

Joint approach to get new neighbourhoods moving

The changes to the mobility system are part of an extremely complex jigsaw, requiring a transdisciplinary approach. “My projects involve partners from science and people who manage the practicalities of mobility, including governments, advisory bodies, mobility providers and special interest groups. The composition of the urban area and its mobility system is made up of 101 components,” Van Arem says. One of the projects uniting all these players is XCARCITY, which looks at the place of mobility in existing as well as newly developed parts of the city. It is based on case studies of Zuidas in Amsterdam, the Merwehaven in Rotterdam, Almere Pampus and the Stadstuinen in Barendrecht. Almere Pampus is currently being developed and Van Arem is, for example, looking at what will happen if the number of parking spaces there are capped.

Experiencing the virtual future

The systems which are currently being developed cannot be roadtested yet and so lack proof of their efficiency. “That is why we are using digital twins, a digital copy of the real situation,” Van Arem explains. “The digital twin contains all kinds of existing data and models, for instance, people’s reaction to price hikes in public transport, the availability of parking spaces in the neighbourhood, or the number of nearby car shares. By fiddling with the nobs, so to speak, and creating different scenarios you can gauge the effects of the various measures. XCARCITY also offers the possibility of VR visualisations which makes things all the more realistic. It shows you what will happen when automated cars navigate a busy street and the effects of making it wider or narrower, for example,” Van Arem says. 

(Not too) detailed models

His background as a mathematician had stood Van Arem in good stead in his current job, he says. “It helps in the way I approach a problem. When I am modelling a transport system I will look for the simplest, most meaningful way of understanding it and capturing it in a model. A model has to be accurate but not too accurate. All you need is the mechanism at the heart of the system. We call it pared-down modelling. But apart from the mathematics, I am also interested in the human aspect of mobility.

Transport and traffic streams are about people and their sometimes unpredictable behaviour, and the way they communicate. I find that endlessly fascinating.”

Japan sets the example

Japan is one of Van Arem’s sources of inspiration when designing future mobility systems. “The Japanese have made great strides in limiting car use. Some streets and roads are even completely traffic-free on some days, to allow children to play or to organise a neighbourhood party. What I like about Japan is the strong role technology plays in society, not for its own sake but always as a way to improve people’s lives. A great example of this is the use of automated vehicles to keep the link between the countryside and the cities alive. In 2030, Japan will have some 10,000 self-driving vehicles, which will counterbalance the lack of drivers. In the Netherlands, this type of shuttle is not yet allowed on public roads.”

Sustainable mobility through self-driving vehicles

Van Arem is convinced self-driving vehicles are going to be at the forefront of sustainable mobility in years to come. “Shared mobility through self-driving vehicles would allow door-to-door transport and private car ownership would fall as a consequence. Automated vehicles would also be electric in most cases which would contribute to a cleaner environment. Sustainability is my main motivation, I want future generations to have a clean earth as well as a properly functioning mobility system. Self-driving vehicles are becoming better and safer so I think it will only be a matter of time before they are allowed on public roads and society will welcome them as a great alternative.” 

Published: December 2024