Publications

People with anxiety disorders may encounter anxiety triggers when (planning to) travel(ing) to a destination, affecting their ability to actively participate in society. Using a Multiple Case Study Design, this paper aims to improve our knowledge on mobility-related problems experienced by people with anxiety disorders and their potential impact on these people’s daily life. In-depth interviews were held with 40 Dutch adults officially diagnosed with anxiety disorders by professionals in the field of psychology. Data revealed that most interviewees experience a mix of problems in using various transport modes. Interviewees often experience the feeling of being locked up and not being able to escape as anxiety triggers. They perceive the mobility system as complex and overwhelming, while mobility-related information can trigger panic attacks or lower respondents’ stress level. Interviewees employ a variety of coping mechanisms: avoidance of transport modes; avoidance of highways, bridges, tunnels; remaining in a familiar, predictable environment; asking for social support when travel is necessary; and searching for adequate travel information to use before and during travel. Coping with anxiety disorders and mobility-related problems may have far-reaching impacts on professional life, including job switching and job relocation. The study shows that it is challenging to define the boundaries of the topic under study and almost impossible to develop a ‘one-size-fits-all’ approach to alleviate this population’s problems. We end with directions for further research into transport interventions that could benefit people with anxiety disorders.

Group travel behaviour widely exists in cities, but has not been well investigated by researchers. To fill this gap, this paper develops a co-existence-based methodological framework to systematically explore the spatiotemporal characteristics of group travel behaviour. We apply our framework to a case study of Shanghai, China, using a one-month tranche of metro smart card data. Results show that most travellers perform a small number of group trips, together with a small number of co-travellers. They usually travel in a dyad or triad group and form far more small social communities than large ones. Group travel behaviour is distinctly different from individual travel in terms of both time and space: group travellers are more likely to travel during weekends, on holidays, and in the afternoons and evenings. They also prefer to perform group behaviour near stations located in the city centre or the centres of new towns in suburban areas, and close to attractions and public facilities. The analysis we present has various potential applications such as improving the management of public events and supporting the design of group ticket policy.

Recent transport equity literature has proposed a sufficientarian approach to transport planning, according to which all individuals would be entitled to a minimum level of accessibility deemed adequate or sufficient. The implementation of this approach would require the adoption of an accessibility standard as a key performance indicator guiding transport investments, land use planning and service provision. While accessibility measures are increasingly operationalised in professional practice, the adoption of actual accessibility standards is rare. In this paper, we explore the barriers for adopting explicit accessibility standards and identify conditions within which such standards could be acceptable to practitioners and policymakers. The paper draws on interviews with professionals in three city-regions in Sweden, complemented with interviews with practitioners from the Flanders region in Belgium and from the UK. We find that authorities are hesitant to define and measure accessibility and that where definitions and performance indicators exist, there is a lack of agreement within and across authorities. The prospect of introducing a standard across the board without attaching any conditions comprises a further reason for shying away from standard-setting. The (dis)integration of transport and land use and complicated administrative and governance structures are described as a further barrier, while demand responsive transport is in some cases considered a panacea to all accessibility problems, making it possible to avoid setting standards. Our findings suggest that standards for minimum accessibility could gain political support if their reach is clearly circumscribed, and their benefits are clearly understood.

In this paper we present and test a survey instrument to determine the prevalence and severity of travel problems, defined as any difficulty a person may experience in reaching destinations due to a poorly functioning transport system. The tool distinguishes between three types of travel problems: difficulties encountered while traveling; reliance on others; and forgoing trips. The deployment of the tool prior to and during the COVID-19 pandemic offers a unique natural experiment. A series of tests for internal validity, consistency, and reliability, including confirmatory factor analysis, support two of the proposed travel problem indices (Reliance and Trips Forgone). Exploiting the natural experiment, known-group analyses and Two-Part regressions delivered evidence for the external validity of the indices and demonstrated the ability of the instrument to elicit insights on travel problems. We end with a research agenda for developing robust measurement tools that can be used in research and policymaking.

There is rich evidence of the various problems people may experience in accessing destinations due to a poorly functioning transport system. Since providing access to destinations is a key purpose of transport systems, it should be important to systematically measure to what extent people experience travel problems. Yet, while some travel problems, such as travel time delays, are measured regularly, data collection on other problems is patchy at best. Against this backdrop, this paper presents a survey instrument to systematically determine the prevalence and severity of a broad range of travel problems among a population. The survey distinguishes between three problem types: difficulties related to actual trip-making (e.g., high travel costs), reliance on others for trip-making (e.g., being dropped off for lack of another option), and forgoing trips (e.g., forgoing a family visit for lack of suitable transport). The instrument is tested in a large-scale survey (n = 1430 valid responses) in four areas in the Tel Aviv region. Confirmatory factor analysis largely corroborates the importance of distinguishing between the three types of travel problems. The resulting latent constructions are then used for cluster analysis. Results show that travel problems are concentrated among a small portion of the population (6% of respondents), who regularly relied on others for trip making and frequently forwent trips. Further analysis showed this group to have low car ownership, below-average income, and a low educational level. The paper ends with suggestions for further improvement of the developed questionnaire and its relevance for transport planning and policy.

This study argues that policymaking guided by public values can help to secure public benefit in technology implementation, for two reasons. Firstly, the emergence and deliberation over plural values can result in more publicly beneficial outcomes; secondly, public values establish the meaningful link between public interest and policy goals. We explore the value bases of arguments around the societal implementation of autonomous vehicles through interviews with professionals. Mapping values on a conceptual model with two dimensions of recognition-neglect and consensus-dissensus, we find that a limited set of values receives recognition, while two distinct sets are contested or neglected almost entirely.

The assessment of transport systems has traditionally focused on congestion and ridership as its core performance measures. These perspectives fail to account for the actual service people seek from the transport system—the ability to reach destinations. Recent studies have shifted to focus on accessibility as a performance indicator, but do not address the question whether the observed accessibility is sufficient for meeting people’s daily needs. This paper contributes to the accessibility literature by (1) applying a people-centered approach to the performance assessment of transit systems and (2) exploring the factors explaining the differences in performance between regions. The paper proposes the Accessibility Sufficiency Index (ASI) as a performance standard. The ASI is based on a sufficiency threshold representing an accessibility level that is assumed to enable adequate access to destinations. The paper uses neighborhood transit job accessibility data to calculate separate ASI scores for different sufficiency thresholds for 49 large US metropolitan areas. Regression analyses show that transit system performance is shaped most strongly by transit vehicle revenue miles, mixed land uses, and activity centering. Importantly, the size of these effects varies by the employed sufficiency threshold, suggesting that transportation and land use factors affect transit performance at different spatial scales. The results have implications for the ways we evaluate transport and transit systems and for our understanding of the factors that affect their performance.

The evaluation of how particular segments of society fare is a common concern in many policy and academic realms, including transportation. The Target group Position Index (TPI) is introduced to assess the relative situation of a target group compared to a larger population. It uses two distinct population-specific benchmarks to determine the relative position of the subgroup: a theoretical worst-case and a theoretical best-case situation. An application of the index to transport is also presented, using 49 of the largest US metropolitan regions as case studies. Job accessibility by public transport is assessed for two population subgroups especially likely to benefit from public transport: adults without a car and adults living in poverty. It is found that the car-less population is comparatively better served by public transport than the poor population. Additionally, regions with a higher TPI score for car-less populations also tend to have public transport systems that better serve their population living in poverty. These results highlight that the proposed index allows for easy comparison across regions, despite large differences in the scale of the variable of interest (accessibility by public transport), the total population, and the size of the target groups (car-less or adults in poverty).

Travel demand modeling has been used as a tool by transportation professionals for defining travel behavior processes and procedures for close to seventy years. With origins tied to the construction of the interstate highway system, our pursuit to understand the connections between human behavior and infrastructure is an under-examined part of transportation planning's history. Many of the underlying assumptions in modeling practice influence transportation legislation, development review procedures, impact fee schedules, parking regulations, and environmental impact statements, to name a few. However, as transportation investments are expected to address new goals such as economic development, environmental justice, improving public health, or mitigating/adapting to climate change, the travel demand modeling practice needs to evolve. Our focus on travel demand as a technical exercise carries implicit assumptions and values that should be scrutinized if we wish to avoid reinforcing the perceived disparities of the past. With new challenges, we need new questions centered around who benefits from investments, the role of transport in increasing access to opportunity, transport costs and location affordability, and how the systems and processes of planning can change to meet more multifaceted goals.

Through the lens of the Social Identify Theory (Tajfel, 1974), this research aims to understand how social identity affects the perception of cycling as a mode of transport among women from different socio-income backgrounds. Using the case study of Tel-Aviv-Jaffa (Israel), we found that cycling is associated with distinct social categories rather than seen as a 'socially neutral' practice. In particular, we found cycling to be associated with 'being a Tel-Avivian' and with a healthy and active lifestyle. Such distinct identification of cycling is likely to enhance cycling uptake among more privileged groups, who are often able to identify with these social categories. In contrast, it may create a barrier for underprivileged groups, who do not identify with these social categories. In addition, we show how e-bikes – which are not identified with privileged groups – do not provide an identifiable alternative for women from all groups, as it is identified with “tough” and “violent” men. Furthermore, we show how cycling, in general, is perceived as “tough”, “dangerous” and as requiring a “constant struggle” over space with other road users, and hence fits a typical “masculine” behavior. Finally, we show how currently cycling is perceived by the underprivileged as a threat to their way of life or even as a symbol of them being pushed out of their neighborhood – a perception that limits cycling uptake among these social groups. These findings underscore the importance of accounting for social identity in cycling research and policymaking, especially in low-cycling contexts.