Stories of #TeamScience

Scientific research is rarely the fruit of individual labour and usually requires the work of a dedicated team. Some topics and challenges are even so complex and comprehensive that they affect all faculties and call for multidisciplinary research and solutions. At TU Delft, a team of researchers and support staff have joined forces to work on the future of mobility. How do we keep our cities clean and accessible? The global population is booming: what can we do to keep the places we know and love within reach?  

In this long read, we talk to mobility researchers Maaike Snelder, Achilleas Psyllidis and Niels van Oort about urban mobility. Finally, we also chat with professor Deborah Nas, who is working on a vision of the future of mobility with her fellow Mobilisers at TU Delft.  

The challenge

Increasing urbanisation is making cities more and more crowded, with an estimated one million people flocking to cities every week worldwide. An with the influx of all these new city-dwellers come parking problems, jammed junctions, more and bigger cars and higher carbon emissions. Mobility, however, is not infinitely expandable, so something will have to change, whether we want it or not.  

That’s why our TU Delft Mobilisers are looking into ways to keep large, densely populated cities and urban areas liveable and in motion. What innovations and technology do we need to make cities pleasant and accessible? What kind kind of vehicles should drive, sail or fly there? How long should it take to get where you want to go? And will the new solution guarantee accessibility for all? 

Maaike Snelder

Land scarcity and rapid urbanisation are pressing issues for cities. For decades, facilitating car use has been a natural direction for public policy because of the many benefits cars have to offer, but we’re fast approaching the limit because of safety concerns, the environmental impact of cars and the space they take up. Maaike Snelder has a background in econometrics and now develops traffic and transport models at TU Delft.  

“I explore combinations of measures we can take to keep cities accessible and liveable while reducing car use, as well as measures to help improve mobility, such as mobility hubs, shared mobility, improved public transport and more space for bikes. There’s no cure-all:  We’ll have to come up solutions that run the gamut to find a way out. The trick is finding a way to optimise multiple different solutions at the same time.”

Climate

“Increasing urban populations, scarce space and increasing dependence on IT and energy networks are rendering cities increasingly vulnerable, and the changing climate is another factor to consider. It only takes one extreme rainstorm for a busy intersection to jam up entirely."

Snelder explains why any solution would have to be multifaceted: “I’ve found that cities themselves tend to promote traditional modes of transport such as walking and cycling. Copenhagen, for instance, has doubled down on encouraging bike use. At the same time, technological innovations like Mobility as a Service, mobility hubs, self-driving shuttles, or waterborne logistics have the potential to drastically improve accessibility. Finally, we need to look at people's behaviour. People have a natural tendency to travel, and it’s very important for the economy that they have the opportunity to do so. Bringing facilities closer to home is a possible solution, as it would drastically cut down on travel time and distance without sacrificing comfort and quality of life, so urban design is also part of the puzzle." 

Car-free city centres

Many cities in the Netherlands are already working on making their city centres car-free. Snelder explains: “Most efforts are still small-scale, but we’re exploring more large-scale methods, as well as identifying key areas in which to pare back on car use. At the same time, it’s very important to ensure that elderly people, for example, can still get around and that shops can still be stocked.” The main challenge is that people do not actually want to get rid of their cars. “After all, the rewards of sacrificing your car - cleaner cities, safe places for children to play and more green space - aren’t immediately apparent.” To help tackle that challenge, Snelder has joined forces with behavioural scientists: “We don’t want to turn the Netherlands into one big car-free zone, but some parts of the country are just full!”  

Niels van Oort

"I’m a public transport researcher for a reason!" Niels van Oort replies when asked if public transport is the solution for the future. “But”, he adds: "There is not one mode of transport that can single-handedly fulfil all social and individual needs. There’s a myriad of factors to consider: where you are, what time it is, where you need to go. There is, however, always an ideal combination of different modes of transport to be found.” Combination is a key part of Van Oort’s vision for the future: “Combination paves the way for innovation. My research interests include sharification, electrification and automation, which can be combined to generate innovation.  I’m a particular fan of small technology with a big effect, like tapping into public transport with your debit card or equipping shared bikes with a smartlock.” 
 

Demand-driven public transport

Van Oort also believes that demand-driven public transport will be a key breakthrough in the near future. “Smart algorithms-like that match demand with supply, like Uber’s, will eliminate empty buses while still ensuring that people can reach their destination.   There have already been various pilot studies for public transport, including flexible systems and hoppers, but a workable solution is yet to be found. Autonomous shared cars or shared taxis that park outside the city centre could help combat the scarcity of space. And while it’s not a very popular opinion, well-functioning trains and buses also get you a long way.” 

Niels van Oort’s goal is to develop an optimal public transport and shared mobility system. Optimal for society as a whole - so cleaner, safer and liveable - and for travellers, who just want to get from a point A to a point B as effectively as possible. In his pursuit of this ideal, he works closely with Wijnand Veeneman: “I could come up with a good public transport system on paper, but I’d need Wijnand’s expert input on governance, not to mention the expertise on vehicles & technology at the faculty of Mechanical Engineering. The great thing about the Mobilisers is that we’re a multidisciplinary bunch: this problem can only be solved if you work together and approach it from different angles. If you try to solve global problems, or even urban problems, on your own, you’re guaranteed to fail.” 

Students know the future

Van Oort frequently works with government agencies and transport companies to ensure that the results of his research are put to use in society. His Smart Public Transport Lab is currently working on research projects with the city of Amsterdam, NS and Arriva, among others. Former Best Teacher Award Recipient Van Oort also finds inspiration in his sutdents. “I love discussing the future of mobility with students. They’re real digital natives, having grown up with technologies like unlocking shared mopeds with your phone. In fact, I dare say that my research agenda is partly determined by what my students tell me is important. Inclusive mobility is currently a hot topic, with one of my students writing a thesis on gender equality in traffic. Other popular topics are shared mobility, sustainability and international rail transport. The master’s course I teach evolves with my students’ priorities. After all, they’re the people who will change the world.”

Achilleas Psyllidis

“People’s movements aren’t random: we want to go places, we want to use services or buy goods, we want those services or goods to come to us, and we want to meet other people. And we don’t just want to meet people we know: serendipitous encounters are a big driver. The question is therefore not only which places can we access, but who else can get there too.” 

Achilleas Psyllidis is an associate professor of Urban Mobility and director of the Urban Analytics Lab. His main research interests are the development of innovative accessibility metrics and what he calls co-accessibility: the accessibility of places for different people. "We measure both accessibility and the odds of you meeting other people, or serendipity. Not only does the chance of serendipitous encounters increase well-being and your sense of security, but it also gets you out of your own bubble. A park, for example, is a great place to meet people from other age groups or cultures.”  

Psyllidis explains why it is so important to include co-accessibility in research and urban planning: “In the past, urban planners would simply say: we want everyone to have access to a park, no matter which park. In reality, ensuring that people end up in the same park is actually quite important, as it it improves vibrancy and the likelihood of serendipity. A municipality that takes the first approach might invest in multiple parks. A municipality that chooses the second will invest in a single park, as well as the roads and public transport services that lead there. It's an important difference indeed." 

Making cities inclusive 

“We have to create opportunities for people to meet, for encounters to happen. To do so, we look at whether urban systems are accessible to residents, whether they’re accessible to all residents or mainly to certain groups, and how we can improve equality.” As a researcher, Psylllidis aims to improve accessibility across the board. "We look at different groups, including children, elders and women, and want to enrich existing mobility research with our new, inclusive insights.” 

Psyllidis explains how COVID-19 illustrated that mobility goes beyond people getting from a point A to a point B. “Urban mobility is also about digital connections and the speed at which goods can travel. While traffic jams eased during the pandemic, the mobility of goods actually increased, as delivery drivers took over the streets. Instead of seeing each other in real life, people started meeting digitally. Our needs didn’t change. We have an inherent urge to have access to everything, and I want my research to improve accessibility for everyone, not just for a certain social class. What’s more, we have to respect the planetary boundaries. You can’t just keep growing mobility, because there comes a point at which you run into planetary boundaries, so greater proximity and connectivity will play a more important role in the future." 

CTwalk Map, a tool developed by Psyllidis and his team, will soon be presented during Mobility Week. “How far could you get from any random point in five minutes, and what about fifteen minutes?”

Deborah Nas

Deborah Nas: "For mobility, we’re exploring different future scenarios with a team of 12 mobility scientists from six faculties - including the three in this article - to glean insights that will help us define what we want to the future to look like.” 

Future scenarios 

Nas favours a method called Strategic Foresight: “The first step is to look at the big picture and identify developments that can impact the future. You then cluster them into several themes and score them on likelihood and impact. The two clusters that are both highly unlikely and highly impactful together form a matrix for four future scenarios. Our scenarios are modelled on a society that’s very open to new technologies versus one that’s very reluctant to embrace them, and on a government that focuses on facilitating free market forces versus one that focuses on shared prosperity. Each of these futures has advantages and disadvantages, and reality will ultimately be a mixed bag." Analysing various scenarios teaches you what really matters, Nas argues: “What do we want the future to hold, and what will our cities and mobility system look like in 2050?”  

Wicked problems 

“In the field of IDE, these are what are known as wicked problems,” Nas continues. “Inaccessible, gridlocked cities are a complex problem with multiple causes that requires a multitude of different solutions. What’s more, all the constituent elements of the problem are constantly changing and affect each other. Optimising the traveller’s comfort, for example, could have adverse effects on sustainability, and prioritising sustainability can lead to mobility poverty among those parts of society that cannot afford sustainable solutions." 

While her vision has not yet been finalised, Nas can share its general thrust: at TU Delft, we’re working on sustainable, inclusive, equal, resilient and safe mobility that promotes healthy lifestyles and contributes to liveable, pleasant cities. To get there, however, we will have to make all sorts of different trade-offs, as some of our goals are mutually exclusive, pure and simple.

Much to be gained 

Nas has always been fascinated by innovative mobility concepts, which is why she’s also on the Supervisory Board at Hardt Hyperloop, a Delft startup developing a hyperloop system. “Mobility is unique in that it affects all of society. Besides, it’s a matter of great urgency. Almost 20% of all carbon emissions are mobility-related, so we can kiss our carbon targets goodbye if we don’t figure out mobility. In many cities, you’ll find parcel delivery vans driving through the same street up to twice or three times a day. These extremely inefficient processes are fertile ground for quick wins, because you improve all the elements involved, from the technology to the infrastructure, from the vehicles to the users and from policy to governance.   That’s also why a multidisciplinary approach comes in so useful.”