↑    Traffic participants, are often irrational, but fortunately systematically irrational — means that remedy the situation with nudging (shutterstock_1085653367).

Robert M. Häusler calls here for an incremental approach to teasing out the inefficiencies and lack of integration between mobility modes.

It’s not really clear if these nudge measures will actually be enough and add up facing the fast-moving mega-challenges of urbanisation and climate change.

       Robert M. Häusler  –   30 June 2019

Nudging towards a mobility and citizen management

Nudging can help us get from A to B faster, safer and sustainable.

The human mobility experienced a revolution with industrialization in the 19th and early 20th centuries. Thanks to the invention and spread of technologies such as trains, cars (and trucks), buses, bicycles, trams and aircraft, it became enormously efficient and easier to get from A to B within a short period of time. With this mobility revolution, however, new problems also arose. After all, as we as human beings are traffic participants, we often act irrationally. The reason for this is our cognitive distortionsOur automated thinking is based on heuristics and these heuristics often mean mistakes of thought in practice, which lead us to behavior that does not benefit us.

Irrationality in transport means that we do not get from A to B as efficiently and safety as we could – and we expose ourselves and other people to greater risks. Fortunately, we are not powerless against our mistakes in thinking about transport and mobility. With so-called nudging measures, i.e. with gentle nuds, we can adjust the mobility context in such a way that the negative consequences of our irrational thinking are less strong or even completely eliminated.

Nudging in the field of mobility and citizen management means that we can have more safety and more efficiency with simple measures. There are mobility and citizen key areas where nudging has the potential to have a major positive impact:

§  Cars, Vans and Autonomous Vehicle

§  Pedestrians and Foot traffic

§  Bikes and Micromobility

§  Aviation and VOTL

§  Public transport

Pedestrians and Foot traffic

If we try to get on foot from A to B, then we are already traffic partner. Although we do not use a transport device such as a car or any other mobility offer, we are part of the entire traffic flow of a city, for example.

The question of safety is essential for pedestrians in a city. Pedestrians are the ‘weakest’ road users: if there is a coming accident between pedestrians and cars, bus, lorry, tram, trains, then the risk for pedestrians is understandably and logically, the largest. Nudging measures can be used to increase the safety of pedestrians, such as pupils on their way to school, easily and effectively. A good example of this is instructions placed on the ground, which encourage you to see if a car is approaching when crossing the road. Such nudges are very prominent in the cityscape of London:

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A simple verbal nudge for pedestrians. (shutterstock_1029819247)

Nudges mounted on the floor are very suitable for pedestrians, because we often have a slightly lowered view when walking or look directly at the ground. This is especially true in the age of the smartphone: we increasingly have a habit of staring at our smartphone and only indirectly perceiving the change. Most of the time, we only perceive the very immediate environment in front of us on the ground. Nudges on the floor are not limited to verbal instructions. There are already very interesting and practical use cases where the verbal instruction is connected to a light or digital screened nudge. Such nudges have a double effect: in addition to the verbal prompt, a dynamic visual signal is added. An example of such a nudge can be found in Cologne:

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A ground light signal (ground light) in Cologne. (Image source)

Nudging in foot traffic can be very simple measures that make a major contribution to the safety of pedestrians or non-vehicle-connected mobility services. Especially in traffic contexts where there is a certain hustle and bustle, such as busy roads, nudging can have a clear positive impact.


Bicycles are very efficient means of transport, not at least in cities and urban areas of the city: bicycles, conventional or electrically operated are compact, flexible in use and largely avoid the disadvantages of motorized vehicles such as noise, environmental pollution, traffic jams or serious risks to other participants of the roadin the event ofaccidents and uncertainties.

Bicycles also have drawbacks; especially when it comes to safety. A serious safety disadvantage, as with other micromobility services, is that since the 1960s most inner-city roads have been designed primarily for motorized vehicles and bicycles, if any, constituted a secondary consideration in road design.

A very simple yet effective safety nudge is to mark lanes for far wheels clearly in color. If the road sections, which bikes are available, are spontaneously recognizable as separate lanes, it is intuitively understandable for all traffic participants who can and should move where and how.

The color marking of bicycle tracks can also be enhanced with additional nudges. For example, bikelanes can be multi-lane so that cyclists can ride in both directions. Multi-lane bike lanes can indicate the direction of travel with very simple arrows and specify behavior for all other road users.

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A two-lane bike lane in Brisbane, Australia. (Image source)

Working with colours and intuitive symbols in the context of cycling still has a lot of potential. A typical example of this is traffic circles; Roundabouts are a very useful measure that can significantly reduce the flow of traffic at intersections. However, it is often not clear how bicycles should behave in roundabouts, both for cyclists and for motorists.  Correctly, they should use the gyroscope as regular as cars, because there is no separate bike lane in the roundabout. Many cyclists ride in the roundabout as if there were still a separate bike lane, which is not the case.

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A problem zone for bicycles that can be tackled with nudging: gyroscope. (Photo by Raphael Schaller)

A second area of bicycle traffic, in which nudging can increase safety, is risk perception and risk behavior. Cyclists generally perceive themselves as risk-neutral, but they sometimes behave more than risk-joyful. This means that Cyclists sometimes over-emphasis on efficiency and taking higher risks to get to the destination faster. Nudging measures make it possible to improve the risk behavior of cyclists in the flow of traffic.

A single and also decisive reason why cyclists on the bikelike to berisk-happyis simply that it is uncomfortable to stop and thenstart again. This is exactly where we can use nudges topics and reduce the level of inconvenience when stopping. An innovative measure for this is footrests and railings to make it easier for cyclists to wait in red.

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A footrest and armrest at a light signal (traffic light) in Chicago. (Photo by Steven Vance)

Nudges to make it as comfortable as possible for cyclists to stop are very innovative variants, such as the canopy: a roof at points where cyclists shoulder had to stop, has the positive effect of providing shade in the sun, drought in case of rain or snow. This allows small stimuli to be created for stopping. For example a canopy for bikes at a traffic light in Hangzhou, China.

Cars, Vans and Autonomous Vehicle 

Car traffic is a thoroughly irrational matter: almost all motorists believe that they drive above average, safe and careful. Not only does this not work mathematically, but it also opens a box of irrational thinking: attribution errors mean that we are irrational when driving, but believe that only the others make mistakes.

There are different problems with car traffic, which increase risks and reduce traffic efficiency: distraction, fatigue, or drugs (especially alcohol). All these problems, however, are based on a fundamental problem, which occurs even if we are not distracted, tired or in toxic: we tend to drive too fast.The faster we drive, the greater the safety risks when driving; no matter if we are fit and cheerful or tired and drunk.

An important goal in car traffic, which can and should be pursued by nudging, is therefore traffic calming.If motorists can be encouraged to drive at a more appropriate speed, safety will increase for all traffic participants — and the flow of traffic will also benefit.Nudging to calm traffic in cars, vans and trucks can take many forms. A tried-and-tested nudging measure is markings on the floor, which occur at ever shorter intervals. As a result, these markings make us feel faster at the same pace. This automatically and intuitively reduces the speed. This measure is particularly useful when a road at slightly higher permitted speeds becomes a lower-speed road — for example, when a road out of the city leads at 80 km/h to the city, where 50 or 30 km/h are permitted.

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Markings, the distances of which become shorter, are available in different variants. (Image source)

In the case of nudging in road traffic, colors can be used as nudges, similar to the bicycle context. On the one hand, colors can have the function of gently steering in a certain direction. Colors can also be used to specifically break the monotony of the grey street. This can make sense if motorists are to be ripped out of automated driving in order to drive more actively and attentively. A possible context for this is road situations, which can quickly become dangerous if speed is too high and too little attention.

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A colorful overpass in 30 million metropolis Chongqing, China. (Image source)

Nudges in car traffic and, more generally, in road traffic can also go in the direction of optical illusions and illusions like VR/AR projections. Nudges as illusions have the purpose of depicting a motif that is unusual in perspective or visually, which leads to traffic participants adjusting their speed. Optical illusions and VR/AR illusions, such as the now famous 3D zebra stripe, can have a very strong effect. However, if the effect is too strong, the illusion itself can become a security risk; for example, when cars regularly make a full braking if the surprise.

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A 3D zebra strip in Iceland. (Photo by Gusti Productions)

Another tried and tested and highly effective nudge in car traffic are radar panels, which measure the speed of the cars and give feedback. It is not really important or necessary that the board indicates the exact speed in km/h. Feedback is more effective if it has a kind of social, human component. For example, if a board does not indicate how fast a car is driving, but only signals with a smiley face whether the speed is ok or not, the effect of the board is stronger. The Nudge is therefore a feedback and observation within the framework of social norms.

Nudges in cars are not limited to the above examples: there are many other ways to contribute with small and even lager adjustments to traffic calming and thus ultimately to the well-being of all traffic participants in a livable city.

Public transport

Compared to individualized traffic such as cars,micromobility or bicycle,public transporthas an essential and sustainable advantage: safety. Passengers on public transport move from A to B at a very low risk level. However, public transport also has a not innegmissible disadvantage: efficiency. Because many people are involved in public transport as traveler and passengers, inefficiency quickly arises: the behavior of an individual passenger can have a negative impact on other passengers; the sum therefore results in cumulative effects of inefficiency.

Inefficiency in public transport concerns two areas: the stage of finding the place where public transport is located and departing; and the phase of boarding and finding spaceonpublic transport.

When visiting or leaving public transport, junctions such as railway stations are particularly important. At one station, different lines and different forms of public transport converge. Accordingly, stations are also full of people who either travel to another location or have arrived at their destination. The central challenge here is the obvious fact that not all people in a station go in the same direction but move around crisscrossing.Nudging measures have two objectives in contexts such as railway stations. On the one hand, the user of the mobility servicesshould find what he or she is looking for as quickly as possible and thus spend as little time as possibleidle. On the other hand, the entire mobility flows should be designed as efficiently as possible, so that the flow of movement remains as unbroken as possible. A simple example of this is escalators. Escalators are ubiquitous at stations and have an important ordering function. However, escalators can also be a bottleneck that cause congestion as soon as many people want to use them. One tactic to reduce congestion on the escalator is the well-known thumb rule of “go left, stand right”. This rule can be conveyed discreetly using simple nudges.

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Footprints as a simple nudge explain the rule “go left, stand right”. Pictured is Zurich Central Station. (Photo by Keystone/Christian Beutler)

There are many possible nudging options for both individual and collective efficiency gains in railway stations and other similar hubs. What is important in this area of application of nudging is maximizing benefits in the sense of Rational Choice. The goal is not to install as many nudging measures as possible, because it creates a nudge chaos that, at worst, creates inefficiencies rather than eliminating them. Nudging in railway stations and similar areas should be used sparingly and purposefully in order to achieve as much impact as possible with as little effort as possible.

The second major area of public transport, where nudging can have a positive impact, is boarding, finding spacein and disembarkingfrom public transport. Public transport usually means that we are not travelling alone as individuals, but that many people are looking for public transport at the same time. This quickly creates inefficiency and proverbial congestion, because passengers have to disembark, and new ones have to board.

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Many people have to get on public transport, look for a place and then get off again. An impression from Tokyo. (Photo by Banter Snaps) 

We tend to be impatient when boarding, finding a place and getting off, because we want to get to our destination as quickly as possible. As a result, our collective behavior often makes the entire flow of movement slower and more sluggish than it should be. It is quite typical, for example, that when we board, we are very crowded at the entrance of a train, but this makes it difficult for passengers to disembark on the train — in the end, our impatience means that we have to wait longer before we board.

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We often do not distribute ourselves very efficiently within public transport, thereby creating cumulative inefficiency. (Photo by Chanh Hsien) 

Our irrational tendency continues within public transport, because we often seek a place in an inefficient way. If, for example, we want a seat, we like to occupy it in such a way that it is rather cumbersome for fellow passengers to take free seats next to us. Typical of this is our tendency to choose a square rather than a window seat — mostly we hope that the window space next to us will remain free and that we will have more space for us.

Nudging for boarding and disembarking movements as well as for space search (whether we want to sit down or stop) is an area in which there are so far few solutions and models missing.  Nudges that move towards social norms and conformism could help here: if travelers are gently shown that, for example, the window seats should be occupied first, this can have a positive impact. The nudges do not have to be static. It is also conceivable to develop dynamic nudging systems, which, for example, first encourage travelers to leave enough space for the passengers disembarking when boarding, and then to guide them to a free space. One way to do this is to use dynamic light signals.


Hardly anything embodies the technological expansion of human mobility as impressively as aircraft or the vertical mobility models. Flying is a form of mobility that far exceeds our biological possibilities: on land and even in the water, we can move under non-consideration autonomous vehicles without technical aids but fly only works with sophisticated technology.

The challenges that exist in public transport are also present in the context of civil aviation, only a significant piece more complex and accentuated. Flying means that passengers coming to the airport or visit an airport, check-in and pass security checks at the airport,wait for their plane in the gate and finally board the plane. The fact that airports are able to successfully carry millions of passengers a year is already a logistical feat. Nevertheless, the whole process of passenger handling can be made even better with nudging measures.

A fundamental challenge in airports is very similar to the challenge in train stations or in megacities: people want to get to where they needor want to go soquickly, but because of the large crowds’ bottlenecks and other inefficient and critical situation may arise. This applies not leastto thecheck-in (incl. baggage drop-off) and the security check. Most check-in procedures are rather rudimentary: passengers must actively search for those electronic or man-operated check-in counters that are relevant to them. This creates a lot of “congestion”; not least because people who stand around and try to understand where they need to go block the flow of people. Similarly, the procedures of security checks have so far hardly been adapted to the cognitive reality of people: passengers are smuggled through imaginative, cold security checks, without considering how the processes can only be done with the simplest nudging measures. such as easy-to-understand instructions could be improved.

A central part of the airport experience is waiting for the plane in the waiting area of the departure gate. This part of flying is emotionally stressful: at the gate we are on the verge of boarding the plane, but we can’t do anything but wait. Delays are the number one factor in mobility’ frustration and stress, no matter what. Even if the plane we are waiting for at the gate is not delayed, the feeling of passive waiting is a feeling of frustration, which at worst increases to anger and aggressiveness. In order to counteract the negative gate experience, nudging measures can be used specifically to make the monotony of waiting more bearable. On the one hand, our hearing and sense of smell can be addressed: appropriate music and pleasant scents can have a positive impact on our minds. In addition, the factor of distraction or employment is central: enough catering options, enough toilets, but also factors such as clearly declared free wireless internet (Wi-Fi) or newspapers provided free of charge and magazines can break the monotony of waiting.

One possible measure to fill planes more quickly would be to let passenger’s board for their seats in a certain way: first, passengers with window seats board the aircraft, then passengers with middle seats, and finally passengers with Aisle seats. This method is sometimes described as a WilMA method, in reference to the English terms “Window”, “Middle” and “Aisle”. This type of efficient boarding can be reinforced with nudging measures, for example in the form of easy-to-understand graphical instructions on a large display in the gate. The WilMA method for boarding can also be used for disembarkation after the arrival of the aircraft. Our typical behavior when disembarking is quite clearly irrational: a large proportion of the passengers stand up and wait for minutes in the aisle for the doors to open. At this stage, just before disembarking, similar nudging measures can be used again as in the waiting area in the gate: every second we have to wait frustrates us. This frustration can be reduced with targeted nudging.

Through these examples, there are opportunities to expand the approach and impacts of nudging by involving people in their behavioral goals. Rare continues to demonstrate that putting people at the heart of behavior change works. We recognize it takes time and energy to address both the journey and the destination of behavior change; and we believe that it is well worth it for both lasting behavior and happier people. Nudging can be and has been an effective tool for shaping the behavioral path and making targeted behaviors easier to do. It draws on many foundational observations of human behavior and non-rational decision-making processes. It is easy, cheap, replicable, and delivers big results through small changes. With that being said, we have found that realizing long term behavior change requires additional insights from behavioral science and other social science fields that transcend human biases.

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