The commuter, a rational decision maker?

Commuters have a very regular decision-making situation and are not subject to strong seasonal or weather-related fluctuations like leisure traffic. Looking at the dust pollution in North Rhine-Westphalia, this topic has a high relevance especially in the Rhine-Ruhr conurbation. Even the ADAC (2020) (General German Automobile Club, Europe's largest motoring association) advocates an expansion of local public transport to reduce dust pollution during rush hours.

Last year, the so-called climate package was adopted. A core element of this package is CO2 pricing for transport and heat from 2021 onwards, initially as part of a fixed-price system (BMU, 2019). Experts consider the pricing to be too low and criticize the simultaneous increase in the commuting allowance. However, transportation policy does not only take place at the federal level; states and cities have scope for shaping the mobility reality of many. While in the literature mostly only single measures of different cities are singled out and described as best practice examples, a systematic analysis of different urban mobility strategies hardly takes place. In this paper, urban mobility strategies will be analyzed with respect to their consideration of current behavioral theoretical foundations. The analysis is based on urban mobility strategies from North Rhine-Westphalia, which were prepared within the framework of the Clean Air Initiative 2017-2020. The central hypothesis of the study is that insights from behavioral theory have been given little consideration so far and that, as a result, the potential of urban transport policies has not been fully exploited.

2.1 Transport policy framework

2.2 Commuting in Germany

More than two-thirds of Germans use cars to get to work. In comparison, just under 14% use public transport, about 8% of German employees walk and 9% use bicycles. (German Federal Statistical Office, 2017). Particularly in rural areas, employees sometimes have to cover long distances to the workplace, so one can say: the smaller the municipality of residence, the longer the commute (infas et. al, 2018). In addition, professionals with an academic degree have the longest commutes on average (infas et. al, 2018). In a survey of car commuters by the ADAC (2019), the main reason given for choosing the car was the lack of public transport services, and no change in public transport services was expected in the medium term. In a survey of professionals and executives by the job platform StepStone (2018), for more than half of car commuters the poor connections were a reason why they could not imagine switching to public transport, and more than 20% would not like to switch to public transport due to the lack of flexibility. Overall, 18% of car commuters surveyed could imagine switching to public transport (Stepstone, 2018).

2.3. Current debate

To understand the at times heated discussions about individual motor traffic, it is important to keep the historical relevance of cars in mind. Cars are regarded as a "defining element of German society" (Canzler and Radtke, 2019 p.5), and the car has been described as the "engine of the so-called economic miracle" (Canzler and Radtke, 2019, p.5) . For many years, the planning ideal of the 'car-friendly city' was pursued and, in part, implemented very successful.

According to Klenke (2007) the commuter allowance played a predominant role in mass motorization, by financially supporting the move to the countryside and thus spurring urban sprawl. Today, the car is taken so much for granted that some people perceive a threatened restriction of car use as a loss of their freedom rights. According to Canzler and Radtke (2019), a fundamental change in transportation infrastructure poses the dilemma that the concrete interests of car owners as potential losers are set against the uncertain benefits of the general public as diffuse winners.

Various developments point to a reversal of the trend; for example, the literature notes that the attitudes of the younger generation could promote a transportation turnaround. A 2014 study by the Federal Environment Agency (2016) indicates that young people are using cars less and are particularly open to using car-sharing services.  However, a study conducted in the same year among vocational school and university students concludes that the car is perceived as a status symbol in an unchanged way and that a general shift away from the car cannot be observed (Schenk, 2017).

3.1 Economic frameworks

3.1.1 Rational behavior
3.1.2 Household theory
3.1.3 Discrete decision models
3.1.4 Hybrid decision models

3.2 Socio-scientific frameworks

3.2.1 Fundamentals of Attitude-Oriented Behavioral Models
3.2.2 Psychological determinants of the choice of transport mode

Overall, it is important to point out that all determinants of mode choice are perceived subjectively, even supposedly objective factors. For example, many studies are not based on objective travel costs; instead, participants are asked to estimate travel costs. Overall, drivers often overestimate travel time and the cost of public transportation (Bamberg, 1996; Fuji et al., 2001). At the same time, many drivers have difficulty estimating the cost of car use (Bamberg, 1996) and equate it with fuel costs (see e.g. Wardmann et. al., 2001).

User friendliness and ride comfort are also subjectively evaluated. In the case of repeated experiences such as the daily commute, according to the peak-end rule, people tend to remember only particularly positive or negative experiences, as well as recent experiences (Kahneman et al., 1997). Sprumont et al. (2017) show in their study that commuters' decision utility and evaluations do not completely coincide. Carrel et al. (2013) examined how the timing of a delay affects the travel experience. For example, long delays or cancellations at a transfer stop were more than twice as likely to cause people to reduce their use of public transportation as delays or cancellations at the origin stop.

3.2.2.1 Affective and symbolic factors

When studying affective and symbolic factors, it is necessary to keep the specifics of studying human behaviour in mind. Steg et al. (2001) emphasize that symbolic and affective motives emerge more clearly when the goal of the research task is not too obvious. For example, they note in their research that respondents mentioned instrumental aspects when they were explicitly asked to evaluate the desirability of car use. With a less obvious research objective, respondents primarily cited symbolic and affective aspects that make car use attractive. Steg et al. (2001) thus suggest that people are unwilling to admit that car use serves many symbolic and affective functions and that drivers rationalize their behavior.

Mokhtarian and Salomon (2001) demonstrate that although most driving has immediate utility, people have an intrinsic need for mobility. In doing so, they argue that speed and motion elicit feelings of control and pleasure, which is why people enjoy driving without a fixed destination and why they may be motivated to undertake excessive trips as a result, even in the context of necessary travel. In their research with over 1300 respondents in the San Francisco region, they find that commuters do not seek complete minimization of travel time. The reported ideal commute time averaged 16 minutes. Only 3% of respondents desired a commute travel time of zero to two minutes, while nearly half preferred a travel time of 20 minutes or more (Mokhtarian and Salomon, 2001).

3.2.2.2 Habit

In general, individuals prefer the status quo. Samuelson and Zeckhauser (1988) define the status quo as non-action or maintenance of the current or previous decision. Their research shows that the status quo effect is also present in situations without monetary gain or loss options, which can be explained in part by the phenomenon that people prefer decisions that require less mental effort (e.g. Garbarino and Edell, 1997). Transportation decisions often represent routine actions, which makes behavioral change much more difficult (Canzler and Radtke, 2019). Because commuting, unlike vacation or excursion travel, is a frequently performed behavior and is usually repeated without conscious thought, commuting behavior is particularly driven by habitual actions. A study by Verplanken et al. (1998) shows that a pronounced habit is associated with a lower intake of information and a less conscious choice of transport mode. Even if a person’s behavioral intention changes, when habits are pronounced, switching to another mode of transportation is unlikely (Verplanken et al., 1998).

Behavioral research has shown that context changes disrupt habits (see e.g. Wood et al. 2005). Following Dahlstrand and Biel (1997) Fuji and Kitamura (2003) argue that in order to switch from car to public transport, it is necessary “to unfreeze driving habits” (p.83). A rather new form of behavioral intervention is represented by nudges, which are intended to induce behavioral change against the background of libertarian paternalism. Nudges can be defined as low-cost interventions that are easy to circumvent (Thaler and Sunstein, 2009). In five large-scale field studies involving nearly 69,000 employees of a European airport, Kristal and Whillans (2020) examined whether nudges reduce car commuting trips. To do this, they sent out letters and emails to promote the employer’s carpooling platform and provided inactive platform users with personalized suggestions for carpooling and advice on opportunity costs. The authors also tested the impact of free weekly bus tickets and sent out information about nearby bus routes. In doing so, they pointed out the possibility of buying reduced-price tickets for public transportation from the employer. In another study, Kristal and Whillans (2020) tested the effects of personalized travel plans and offered face-to-face counselling sessions. Overall, they found no evidence across studies that nudges changed commuting behavior. Kristal and Willians (2020) explain the lack of effectiveness of nudges by arguing that, unlike successful studies in other areas, the intended target behaviour did not match the individual’s self-interest and suggest hidden affective or symbolic motives of car commuters. Overall, the authors conclude that nudges are not very effective in changing habitual behaviours such as commuting (Kristal and Whillans, 2020).

Various studies examine the effect of temporary structural changes. For example, Fuji et al. (2001) find that an eight-day highway closure can lead to an ongoing change in mode choice. In their study, Fuji et al. (2001) surveyed 335 car commuters daily about their mode choice during a highway closure in Japan. They observed increased use of public transportation, the persistence of which was closely related to how frequently the commuter had previously used the car. Fuji et al. (2001) reasoned that this relationship was due to the salience of habit. Fuji and Kitamura (2003) showed the positive effect of temporary price incentives on public transport use in another study. In their study, 23 Japanese car drivers were given a free monthly bus ticket, and they used the bus 20% more often after the free month expired. A Swedish study investigated the effects of free monthly tickets with a much larger experimental group of over 370 participants and confirmed the hypothesis that temporary price changes can have a long-term effect (Thoegersen, 2009). The monthly tickets were generally applied to public transport in the Copenhagen metropolitan area and, due to their high monetary value, represented a substantial gift designed to attract the attention of motorists. The free tickets led to a doubling of the use of public transport, and the positive effect remained even after half a year. However, Thøgersen points out that the increase is at a low level. Thus, the number of commuter trips by public transport increased from 5 to 10%, and in the long run 7% of the participants used public transport for commuting to work (Thoegersen, 2009).

In sociological transport research, the relevance of key events is emphasized. Here, it is assumed that the timing of habit-breaking interventions is crucial. Van der Waerden et al. (2003) define key events as important personal life events that lead to a reconsideration of current behavior. Scheiner and Holz-Rau (2013) categorize key events relevant to the transport sector into the three life domains of household and family biography, work biography and residence-related biography. In addition to classic key events such as changing jobs or moving, events such as the birth of children or divorce can also lead to changes in transportation behavior (Holz-Rau and Scheiner, 2003).

Thøgersen (2012) noted in a second examination of his data that the effect of free monthly passes was limited to drivers who had changed either residence or job within the previous three months. Surprisingly, members of the control group who did not receive a free monthly pass also reduced their already low use of public transportation when they changed residence or job. Other studies support the observation that job changes and changes in residence are more likely to lead to a switch to another mode of transportation. For example, a British study of 15,200 workers, showed that nearly one in five car commuters switched modes when they changed employers (Clark et al., 2016). Although the results can be explained primarily in causal terms by a change in distance, the life events of changing jobs and moving also have an effect on mode choice that is independent of distance. Clark et al. (2016) conclude that behavioural interventions on transportation choice are most effective when directed at new employees. Young adults entering the labour market should be targeted, as they are particularly prone to commuting by car.

4.1 Regulatory instruments
4.2 Planning instruments
4.3 Market-based instruments

4.3.1 Subsidies
4.3.2 Taxes
4.3.3 Quantity restrictions

4.4 Information and appeals

Information and appeals, so-called soft instruments have found great resonance in the political discourse in recent years. Schwanen et al. (2012) justify this popularity by arguing that, in line with the individualistic view of human beings in Western societies, soft instruments assume that the individual is the central actor in transport decisions and thus a relevant starting point. However, the sole application of soft instruments in the transport sector usually shows hardly any effects (see e.g. Steg, 2005; Tertoolen et al., 1998). Tertoolen et al. (1998) point out the danger that pure appeals to motorists to limit car use may even cause negative dissonance. Thus, soft instruments primarily have a “synergistic relationship” (Beckmann, 2016, p. 749) with hard regulatory, construction, and financial measures.

Addressing individuals should address affective and symbolic motives (Steg, 2005) so public transport can be advertised affectively in campaigns. Various authors suggest focusing on the trustworthiness of public transport (Mann and Abraham, 2006; Vugt et al., 1996). Paulssen et al. succinctly state, “Unfortunately, nobody is selling transit the way automakers are selling cars” (2014, p.886).

5.1 Procedure and evaluation
5.2 Discussion

The analysis of 20 mobility strategies shows that municipal strategy papers do not include the assumptions and theoretical foundations underlying the selection of their measures at all or only in passing. This makes it difficult to systematically test these basic assumptions and the suitability of the measures for their theoretical effectiveness. In some cases, it is still assumed that the mere improvement of public transport services and pure information campaigns lead to a change in transport mode choice. Some excerpts contradict the current state of knowledge in transport science. For example, the Aachen master plan describes that for a greater use of the Park and Ride season ticket, which entitles the holder to park the car and use buses, “expert opinions (…) at the time formulated a price of 25 Euro for commuters as an incentive to switch to public transport” (2018, p. 23) . In contrast, the Dortmund master plan (2018), which plans a similar measure, states that an inner-city parking management would have to take place at the same time in order to achieve a switch to public transport after arriving by car.

The Oberhausen master plan (2018) even assumes that explicitly habitual car drivers will switch to public transport by means of price incentives. Thus, bringing car-affine people to public transport is to be done through price promotions in the form of free public transport tickets as an incentive, which is in clear contrast to the research. The Bielefeld master plan (2018) also assumes a strong rationality of the transport users. With regard to the operational mobility management it is noted that users often lack information to be able to compare the different mobility alternatives with each other.

Only a few master plans recognize the role of habit. The master plan of the city of Bonn for example states that commuters are difficult to address because of their habitual behavior, but “other trip purposes such as shopping and leisure offer additional opportunities to try out new habits without going by car” (2018, p.78). Although some cities mention the measure of new citizen marketing, only three cities address the issue of free public transport tickets as part of new citizen marketing. Otherwise, it is often given the impression that simply providing information to new citizens serves as a measure (e.g. City Gelsenkirchen, 2018). Overall, the analysis suggests that the central factor of habit and the relevance of key events for behavioral interventions is rarely recognized.

Overall, many cities mention the expansion of bicycle infrastructure at the expense of cars and the introduction of bus lanes. However, the formulation of restrictive measures is sometimes very cautious. For example, the Dortmund master plan formulates: “the possibly necessary repartitioning and redesign of the road space may lead to reduced parking space for motorized traffic at individual locations” (2018, p.98). However, the analysis results indicate that the need for a mix of instruments is increasingly being recognized.

The analysis of the communication instruments used confirms the impression that many cities assume a conscious, rational choice of transport mode, which can be significantly influenced with appeals and information. More than half of the cities examined describe the measure of general information dissemination for a more conscious choice of means of transport, which is not very promising according to the study results listed. Many cities promote corporate mobility management, which is initially a logical starting point, especially for targeting new employees. However, success depends to a large extent on the will of the individual employer. In this context, it is questionable that employers should adopt unattractive, restrictive measures such as decreasing the number of employee parking and pricing employee parking, which contributes significantly to the effectiveness of the measures.

It is remarkable how many NRW municipalities focus on improving the availability of alternative modes of transport in order to influence commuter traffic. This seems to be based on the notion that commuters permanently examine the hard factors (frequency, price, connectivity) of their transport options and make a daily decision on this basis. This assumption has been refuted by numerous studies both in terms of information (3.2.2.) and motives (cf. chapter 3.2.2.1.) as well as the effect of habit (cf. chapter 3.2.2.2.). The restriction to a service improvement, no matter how well planned, runs the risk of having hardly any effect and thus wasting resources.

If improvements in public transport services are accompanied by information campaigns, this takes into account the fact that decision-makers do not have complete information at their disposal and, for reasons of efficiency, do not permanently seek new information. In addition, it would be recommended to consider the power of habit and emotional factors in favor of the car in order to further increase the effectiveness of supply improvements.

The affective and symbolic decision factors of commuters in their choice of transport mode could be particularly clearly demonstrated in models of choice behavior if the modeling differentiated the target groups according to similar characteristics (cf. Chapter 3.2.2.1.). The use of this insight could lead to improved effectiveness in the planning of transport policy measures, which seems particularly conceivable for soft measures such as incentives and campaigns. The well-considered disaggregation of transport users as well as the separate consideration of the different transport contexts (inner city, suburb, rural area) seems to be particularly advisable when compiling a balanced mix of measures. Especially for the group of commuters, who cause a very relevant traffic flow, recent studies on mode choice point to the central importance of habit. This factor is already mentioned in some of the examined master plans of NRW cities (cf. chapter 5.2). A suitable starting point is to target commuters after habit-breaking key events such as starting work or moving house.

In addition, it could be useful to take measures that do not aim at a complete switch from the car to an alternative means of transport, but rather promote habit-breaking in principle. These could be special promotion days or offers, but also restrictive measures such as route closures or car-free days. Any measure that leads to more flexible use of transport options paves the way for a gradual and sustainable traffic turnaround. Especially in a decision-making situation that is demonstrably shaped by emotional factors and attitudes (cf. Chapter 3.2.2.2.), the interlocking and step-by-step approach plays a special role.

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