# The Role of Infrastructural and Psychological Factors in Sustainable Transportation Mode Choices
## 4 Discussion
Refining the conceptualization and measurement of climate change perception itself--perhaps focusing on perceived behavioral control--could also yield more informative results and deepen our understanding of sustainable travel choices. The two-stage sampling design comprising an opportunity, and a random sample is susceptible to self-selection bias and potential inconsistencies in participant characteristics. This and the mostly online questionnaire might have led to an over-representation of young individuals already interested in sustainable mobility. The generally high awareness and small variance in climate change perception might have impacted our results, diminishing existing effects in the population. Notably, the achieved sample size was relatively small, suggesting that the population may be difficult to access. Under the given circumstances, the use of this sampling method is acknowledged as a limitation, albeit a necessary compromise given the scarcity of alternative approaches. Moreover, our study did not include active mobility options, such as walking and cycling, as dependent variables, despite their growing importance as sustainable modes of transport. Active mobility offers low-carbon alternatives to MIT and PT while also providing health benefits and enhancing the quality of public spaces through decreased noise and air pollution [54]. Incorporating walking and cycling could have provided a more comprehensive understanding of travel mode choices, especially within the context of the shift towards greener transportation options. When building on the presented insights, active mobility options should be considered. Also, the limited sample size could be a subject of critique. The implemented questionnaire was rather long, thus bearing a bigger respondent burden [55]. At the same time, the extended questionnaire gave the possibility to integrate innovative psychological variables besides well-known predictors and made the present research possible. We counteracted the limited sample size by applying robust statistical methods (bootstrapping) and by analyzing a less complex regression model. The study's interdisciplinary approach offers valuable starting points for future research and practical guidance for policymakers and traffic planners. One key finding is that infrastructural, as well as psychological factors, play a role in the choice of MIT and PT, and both should be considered when studying decision-making processes. Therefore, decision-making on future mobility concepts should incorporate not only infrastructural considerations but also individual perspectives, such as attitudes, traits, and fundamentals of behavioral change. In this context, railway accessibility and car attitudes remain crucial. When exploring what drives PT use, both infrastructure improvements and the shift away from a car-oriented attitude should be emphasized. Additionally, MIT usage is predictedby the factors of center accessibility and adaptability--aspects that are relatively stable and difficult to modify, given the fixed nature of city centers and personality traits. To effectively shift behavior away from MIT, it is essential to identify and target other, more malleable factors. At the same time, adaptability is a variable relevant to adaptive performance [56] and, thereby, behavior change. Future research should consider the insights provided in this study while also considering change intentions and actual behavior change.