Transportation plays a key role in urban sustainability planning and urban greenhouse gas emission reductions. Globally, cities have established sustainability agendas and policies to guide the shift from traditional private automobile dependent transportation systems towards an increased use of public transportation, cycling, and walking. While the surrounding physical urban form and governance structures condition public transportation services, there are also many other factors to consider when discussing sustainability. As such, comprehensive planning and policy-oriented assessment frameworks that are independent of local conditions are still largely missing in literature. This paper presents a Public Transportation Sustainability Indicator List (PTSIL) that provides a platform for an integrated assessment of environmental, economic, and social dimensions of sustainability through an indicator-based approach. To demonstrate its use, the PTSIL is applied to analyze the policy documents of public transportation agencies in Helsinki, Finland, and Toronto, Canada. The results show that while both cities achieve relatively high scores in all dimensions, there is still high variability among individual indicators. The PTSIL presents a missed stepping stone between descriptive definitions of transportation sustainability and case specific sustainability performance assessments, offering an opportunity within the planning and policy-making sectors to review, assess, and develop public transportation services comprehensively.

The volume of urban transportation sustainability assessments in academic literature has steadily increased over the last two decades. This paper targets these studies through the first systematic literature review to construct a synthesised and critical overview of how urban transportation sustainability is in fact assessed. The sample consists of 99 peer-reviewed articles retrieved via three scientific search engines. The results reveal a Europe-centric and single-case focus, a strong interest to introduce new indicator systems with limited references to previous work, and a lack of qualitative approaches and stakeholder diversity regarding the assessment methods. Nearly 2400 indicators are identified in the articles with significant variation in their use. Furthermore, the comprehensive accounting for sustainability is often overlooked, and the inconclusive assessment results are often noted by the authors of the sample articles themselves. Our findings signal that the research field is highly fragmented and to some extent fails to accumulate knowledge generated by past studies and to comprehensively operationalise the concept of sustainability. The identified shortcomings of the assessments and their implications for transportation policy-making and planning are highlighted, and based on our results recommendations to develop more reliable, comparable, and inclusive sustainability assessments for the urban transportation sector are made.

Diverse physical features of urban areas alongside socio-demographic characteristics affect car ownership, and hence the daily mobility choices. As a case of sustainable mobility, we explore how various urban environments and socio-demographics associate with the spatial and social distribution of household car ownership and carlessness in the Helsinki Metropolitan Area, Finland. Three urban fabrics characterizing the study area are established based on the transportation mode (walking, public transportation, or automobile) the physical urban environment primarily supports. The national level Monitoring System of Spatial Structure and Urban Form database, and the National Travel Survey (2016) are utilized to further include spatial and socio-demographic variables into our analysis across these fabrics. Our results show that households with and without cars differ in terms of residential distance to the city center, neighborhood density, house type, and socio-demographic profiles. Single pensioners and students are most likely to be carless, whereas families represent the opposite. Within the carless households the differences are also evident between different groups. For the more affluent households residing in dense and well-connected areas, and mostly possessing driver’s licenses, carlessness is presumably a choice. Contrarily, many other carless households represent the less affluent often located in the more distant, low-density, and less accessible areas, while also possessing less driver’s licenses, making carlessness more of a constraint, as the local urban fabric does not support such lifestyle. Consequently, carless households should be increasingly recognized as a focus group in sustainable urban planning in terms of identifiable best practices and potential vulnerability.

No abstract