The symbiosis of mobility, part 2

If you did not read the first entry of this short series, we highly recommend doing so before continuing – you can do so here.
This second entry is about commensal mobility, in which the interaction between the two actors gives one of them an advantage, while the other remains unaffected.


Note that we deliberately skipped neutralism, since it is a special case of interaction that has absolutely no effect upon its actors whatsoever. Most ecologists would argue that true neutralism is virtually impossible and therefore does not even exist. Moreover, within the field of mobility, nothing comes to mind promptly that would classify in this category. Therefore, we will leave it aside for now. If any of you might know good examples of mobility suiting the term “neutralism”: feel free to let us know!

Commensalism in its turn can be divided in several subcategories, depending on the nature of interaction. We’ll just go over a few of them that seem most interesting to us.


Phoresy is perhaps the most straightforward form of interaction in this entire series, because it goes straight to the root of mobility. In biology, we can speak about phoresy when one animal is attached to another exclusively for transport. You can find tons of beautiful pictures on the web showing lice hitching a ride on the back of a larger insect. The larger animal experiences no downside or benefit from its passengers.

Translated from Franquin's comic Gaston n°13: "Lagaffe mérite des baffes", page 23. (Editions Dupuis, 1979)

Translated from Franquin's comic Gaston n°13: "Lagaffe mérite des baffes", page 23. (Editions Dupuis, 1979)

Unlike the suction seat that divests income from the bus company (as presented in our previous post), the neat invention of Gaston is not having any influence on the cars. The vehicle is arguably light enough not to affect the performance of its "engines" in urban traffic. Its attachment, hitchhiking and detachment might stay unnoticed to the motorised driver.

Apart from crazy inventions, there are also more down to earth examples of phoresy in mobility. Think about a stroller that you can fold in the back of your car, a hoverboard or monowheel that you can take on the bus, or even a simple folding bicycle that allows you to commute partly by train.

Part of the pleasure of the cyclist is to redefine the term 'transport'. (...) Folding bikes are an excellent example. No means of transport is as suitable in combination with other modes of transport. A folding bike goes in the trunk of the car, on the bus, on the train, in the subway. (...) [The folding bike cyclist] does not expect my fanciful Utopian city with only monorail and cyclists, but combines the existing means of transport. He makes a quick metamorphosis into subway passenger. Or jumps on a bus.

Translated from: Hans Declercq, "Een filosofie van de fiets - Londense notities", De Bezige Bij, 2012, pp. 145-146
The metamorphosis of a folding bike cyclist as phoresy. Image courtesy of Brompton.

The metamorphosis of a folding bike cyclist as phoresy. Image courtesy of Brompton.


Inquilinism is the use of a second organism for permanent housing, like certain birds that live in holes in trees. In mobility, we could argue the "house" to be the infrastructure of a certain transport mode, like a parking, a railway or even a pedestrian tunnel. When infrastructure is permanently abandoned or temporarily unused, neo-mobilis can claim it and introduce a completely new use to it.

During the last months of 1973, several governments of European countries declared a number of car-free days. In an attempt to safeguard oil reserves during the occurring oil crisis, motorists were not allowed to use their cars on specified Sundays. As a result, roads remained empty and were gracefully occupied by citizens in a variety of ways. Many cities still organise car-free Sundays on a regular basis, although mainly motivated by ecological awareness.

Inquilinism on abandoned roads in the Netherlands, 1973. Images courtesy of Hollandse Hoogte and ANP.

Inquilinism on abandoned roads in the Netherlands, 1973. Images courtesy of Hollandse Hoogte and ANP.

In urban renewal projects, this principle can contribute significant inspiration to questions about obsolete infrastructure. The High Line in New York City is perhaps the best known urban example of inquilinism. Created in the late 2000's, it is a linear park, built on an elevated section of a disused railroad track. Where trains used to ride until the early 1980's, now pedestrians stroll around above the regular traffic.

The concept of using infrastructure to your advantage can occur on a much smaller scale too. Almost a decade ago, Czech artist Tomáš Moravec modified a standardised EUR-pallet to fit his city's tram tracks. His approach aimed to bring change into the spatial perspective of a passenger in motion. One could skate the pallet guided by a map of the city lines.


Much more recent, Sebastian Lilge made use of the very same principle of inquilinism for the development of yet another neo-mobilis device. The created apparatus is part of his ongoing research towards the understanding of opportunities and boundaries in symbiotic mobility. Like the previously presented suction seat, it needs to be seen in the light of incitement rather than approached as an effective form of transportation.


The almighty Wikipedia describes metabiosis as a more indirect dependency, in which one organism creates or prepares a suitable environment for a second. This actually frequently happens in our daily environment too. In many cases, cities make great efforts to increase accessibility for prams, wheelchairs, and elderly people. The smooth surfaces in combination with "aiding obstacles" like banisters or benches are ideal grounds for skaters to perform tricks or to comfort their ride.

Stay tuned for the ultimate part!

(Wouter Haspeslagh, Sebastian Lilge)