It’s all about the money! Nudging sustainable mobility, according to science.

Last year, traffic congestion in our country has caused time losses, increased fuel consumption and higher pollution, resulting in a cost of more than 5 billion euros. The need for sustainable mobility solutions has never been more pressing. From bustling city streets to quiet suburban lanes, our modes of mobility play a pivotal role in shaping the environmental landscape. Yet, despite the mounting urgency, embracing sustainable transportation practices often feels like an uphill battle. In this blogpost, we delve into the scientific literature to shed light on the potential power of nudges to steer individuals towards more eco-friendly choices in their daily commutes.

Even in the scientific literature, the tenacity of our private vehicle use is highlighted. Private vehicle users are constantly confronted with the negative aspects of their private vehicle use (such as traffic noise, congestion, and air pollution) but still persist in their commuting behavior. In fact, they do not seem to realize that they are actively contributing to the problem. These results show that commuting behavior is strongly driven by habits. Therefore researchers advise that mobility policies should also target the private vehicle users’ responsibility in negative transportation consequences, and point them to more sustainable alternatives. It’s no coincidence that that’s exactly what most nudging studies have attempted to do.

Currently, every mobility provider seems to have its own mobile app. One of the current trends in nudging sustainable mobility is using apps to provide more personalized information to their users. This type of service already exists under the term MaaS (Mobility as a Service), but is currently moving towards a more elaborate approach by also including data on the weather, traffic situation, parking occupancy and bike sharing opportunities in order to inform users thoroughly on the most interesting and sustainable routes. It is argued that the easier it is for people to find the relevant information, the more attractive it will be for them to use it as the default choice of mobility. In addition, some providers are experimenting by including even personality measurements to adapt the app even more to the users’ wants and needs. Unfortunately, there is no clear information yet on the effectiveness of this approach.

Some studies have focused on testing different communication strategies within these apps to see which nudges are most effective. When awarding commuters for their sustainable choices, studies suggest that digital rewards, praise, competition and gamification are not that effective. Financial incentives, e.g. in the form of discounts or tax benefits, does seem to be an effective trigger. Highlighting the environmental benefits of their choices also had an effect in one of the studies, but only on 25% of the participants.

You do not need to be tech-savvy to start to nudge; some nudges can be spread via flyers and letters. We see mixed results in convincing people to change their mobility behaviors when social norms (e.g. “It’s fun, let’s do this together”) are communicated via printed media. However, an economic incentive (e.g. “take part to win a bike”), again, does seem to do the trick in several studies, even long after the incentive has been removed. Action planning interventions that motivate individuals to actively plan their commute in their calendar, or creating communities to discuss commuting experiences, does not result in more sustainable mobility.

Redesigning the look of a public transport card, thereby labeling the passengers as more sustainable, might be an easy and effective nudge as well. Researchers in the Netherlands labeled the passengers on three bus lines as sustainable travelers by printing it on their public transport card. This intervention increased the total number of bus rides on this line, while no such increase was observed on bus lines with the standard transport card look.

Finally, a free public transport trial day once a year seems to be an interesting motivator for some people, as 70% of the participants of this trial who usually take the car to work report to use public transport more often in the future. It is unclear, however, if they merely report their intentions, or if they indeed plan to act on this intention.

We particularly enjoyed one specific study that attempted to nudge Porsche employees into adopting electric vehicles. Employees use company or lease cars for 12 months, after which, the employees can choose a new model using an internal ordering system.  Three types of messages were communicated to the employees when ordering a new car, either via emails or pop-up notifications: an emotional message (“the heart electric, the soul Porsche”), a normative message (“be an ambassador for a sustainable Porsche future”) or a gain message (“exchange gasoline for electricity and reduce their monthly operating costs by EUR 100”). As you can probably predict by now, the (economic) gain message had the strongest and longest effect on electric car choices (albeit still limited in durability).

As always, nudging is no one size fits all. When it comes to nudging sustainable mobility, many of the traditional nudges are not that persuasive, however, money in particular does seem to do most of the talking. Whereas nudges can definitely work in certain contexts, as a rule of thumb, you should not apply nudges mindlessly and hope for the best. To increase your chances of effectiveness, you need to be aware of the scientific evidence and background of (the application of) nudges, and adapt it properly to your specific situation. And don’t forget to thoroughly evaluate its effectiveness, with at least a before and after measurement. Or in the words of Adam Savage of Mythbusters (picture source: Mythbusters on X):

Do you want to become a nudge scientist yourself, or just want to know how to apply the rules of the art? Then keep an eye on our website! Sapience regularly offers workshops so that you can apply nudges in a responsible way.

In the same light of transparency, a brief description of our methods. We performed a semi-systematic literature review of all recent scientific articles, published in the last 10 years, on nudging, sustainable mobility and transportation. The latter terms are a key aspect of the query, so note that we did not include articles on sustainable behavior in general. In addition, we only included studies that were performed in Europe and one online survey study, resulting in 12 retained articles. We synthesized the results of these studies in the current blogpost.

Did we spark your interest? You can find all our scientific references below. Do you have a burning question on marketing or sustainability that needs a literature review and don't know how to get started? Sapience is always more than happy to help you out!

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Anagnostopoulou, E., Bothos, E., Magoutas, B., Schrammel, J., & Mentzas, G. (2018). Persuasive interventions for sustainable travel choices leveraging users’ personality and mobility type. In Persuasive Technology: 13th International Conference, PERSUASIVE 2018, Waterloo, ON, Canada, April 18-19, 2018, Proceedings 13 (pp. 229-241). Springer International Publishing. https://doi.org/10.1007/978-3-319-78978-1_19

Anagnostopoulou, E., Urbančič, J., Bothos, E., Magoutas, B., Bradesko, L., Schrammel, J., & Mentzas, G. (2020). From mobility patterns to behavioural change: leveraging travel behaviour and personality profiles to nudge for sustainable transportation. Journal of Intelligent Information Systems, 54(1), 157-178. https://doi.org/10.1007/s10844-018-0528-1

Decrinis, L., Freibichler, W., Kaiser, M., Sunstein, C. R., & Reisch, L. A. (2023). Sustainable behaviour at work: How message framing encourages employees to choose electric vehicles. Business Strategy and the Environment, 32(8), 5650-5668. https://doi.org/10.1002/bse.3441

Franssens, S., Botchway, E., De Swart, W., & Dewitte, S. (2021). Nudging commuters to increase public transport use: a field experiment in Rotterdam. Frontiers in psychology, 12, 633865. https://doi.org/10.3389/fpsyg.2021.633865

Gravert, C., & Collentine, L. O. (2021). When nudges aren’t enough: Norms, incentives and habit formation in public transport usage. Journal of Economic Behavior & Organization, 190, 1-14. https://doi.org/10.1016/j.jebo.2021.07.012

Hauslbauer, A. L., Schade, J., Drexler, C. E., & Petzoldt, T. (2022). Extending the theory of planned behavior to predict and nudge toward the subscription to a public transport ticket. European Transport Research Review, 14(1), 5. https://doi.org/10.1186/s12544-022-00528-3

Lieberoth, A., Jensen, N. H., & Bredahl, T. (2018). Selective psychological effects of nudging, gamification and rational information in converting commuters from cars to buses: A controlled field experiment. Transportation research part F: traffic psychology and behaviour, 55, 246-261. https://doi.org/10.1016/j.trf.2018.02.016

Loidl, M., Kaziyeva, D., Wendel, R., Luger-Bazinger, C., Seeber, M., & Stamatopoulos, C. (2023). Unlocking the Potential of Digital, Situation-Aware Nudging for Promoting Sustainable Mobility. Sustainability, 15(14), 11149. https://doi.org/10.3390/su151411149

Máca, V., Ščasný, M., Zvěřinová, I., Jakob, M., & Hrnčíř, J. (2020). Incentivizing commuter cycling by financial and non-financial rewards. International journal of environmental research and public health, 17(17), 6033. https://doi.org/10.3390/ijerph17176033

Mauro, S., Shinde, S., Arnone, M., Zamith, V. M., De Rosa, G., & Pietroni, D. (2022). The role of awareness of mobility offers and nudges in increasing sustainable mobility habits of citizens: a case study from the Munich region. In 2022 IEEE 46th Annual Computers, Software, and Applications Conference (COMPSAC) (pp. 1678-1683). IEEE. https://doi.org/10.1109/COMPSAC54236.2022.00267

Olsson, L. E., Friman, M., Kawabata, Y., & Fujii, S. (2021). Integrating Planned Behavior and Stage-of-Change into a Cycling Campaign. Sustainability, 13(18), 10116. https://doi.org/10.3390/su131810116

Silvestri, A., Foudi, S., & Galarraga, I. (2022). How to get commuters out of private cars? Exploring the role of perceived social impacts in mode choice in five European countries. Energy Research & Social Science, 92, 102811. https://doi.org/10.1016/j.erss.2022.102811