International Journal of Sustainable Transportation最新文献

Shared mobility has brought many disruptive changes to urban transportation systems all over the world. Shared bikes have proven to be among the most successful and influential travel tools in attempting to alleviate the last-mile problem – the difficulty in getting people from transportation stations to their final destinations. This study aims to investigate the impacts of built environment factors on bike-sharing trips. Although many studies have explored these impacts, most have focused on the impacts of urban function, and have paid insufficient attention to the cycling environment. This study used multi-source data, including street view images (SVIs), points of interest (POIs), digital elevation models (DEMs), and road networks, to fully identify the influences of the built environment from five dimensions. The multiscale geographically weighted regression (MGWR) method was used to investigate the impacts of the urban built environment on bike-sharing usage. The results found that high-density roads, recreational POIs, and residential POIs all had positive impacts on the volume of bike-sharing trips in residential areas on weekends, whereas urban greenness negatively impacts bike-sharing usage in parks, because of strict regulations promulgated by local governments. Moreover, the impacts of high-density street networks and residential communities had strong spatial non-stationarity, while the influences of other built environment factors, including road gradient, eye-level greenness, and urban function mixture, were demonstrated spatial stationarity. These findings can facilitate local governments’ and enterprises’ efforts to improve the cycling environment and ensure the efficient management of shared bikes.

Addressing the need for curbing private motorization and car dependency while reducing inequalities associated with transport requires an in-depth understanding of the individual and collective practices, attitudes, and experiences of urban accessibility and mobility of populations across diverse socio-economic backgrounds. This paper builds on qualitative research methods and a framework of transitions to sustainable mobility to examine the links between travel needs, preferences, attitudes, and structural factors such as urban form, poverty, and informality at different scales. It proposes qualitative methods and evidence for accessibility-centred analysis to enrich policy and practice in cities across Sub-Saharan Africa (SSA), using Sierra Leone’s capital, Freetown, as a case study. While the volume of literature on urban mobility, accessibility, and land-use in SSA is increasing, scholarship on cities in Western Africa remains limited. The study examines four neighborhoods with different levels of access and motorization. It interrogates participants’ perceived accessibility, how they shape differentiated everyday mobility and land-use practices at the individual and collective level, and its implications for urban accessibility and sustainable mobility in the medium to long-term future. We found that perceived accessibility influences everyday mobility and land-use practices and the attitudes of individuals in diverse communities toward sustainable mobility by driving them to trade off immediate needs with long-term risks and exposures, imaginaries of motorized futures, as well as collectively transform the functional and physical configurations of the built environment to address their most critical needs in the absence of suitable top-down transport and land-use interventions.

The concept of Urban Air Mobility (UAM), an on-demand aviation service using air vehicles for urban short-distance trips, such as electric vertical takeoff and landing aircraft (eVTOL), has recently drawn public attention as one of possible solutions to traffic congestion in metropolitan areas. We present an optimal planning framework for fleet size and vertiport numbers using generalized cost models of UAM trip chains with two different ground access modes for first and last mile trips, including taxis and robotaxis (i.e. autonomous taxis or shared autonomous vehicles). As it is a relatively new and untested mode of transportation, our research aims to provide a decision-making tool for initial UAM system planning and analysis of its economic feasibility, appropriately considering its unique characteristics, such as high free-flow speed, low circuity, needs for ground access, and specific cost factors, such as vertiport and electric vertical takeoff and landing aircraft costs. Through a parametric study, we quantitatively examine the necessary conditions for UAM, with or without ridesharing, to become more economically viable than other ground-only modes. The study confirms that UAM can have potential economic benefits especially in large cities with longer average trip lengths and severe traffic congestion, where the average ground vehicle speed is low.

Numerous studies estimating transport CO₂ emissions in developing countries were on the large scales and few provided high-resolution mapping of transport CO₂ emissions from different transport modes according to their respective distribution and diffusion patterns. This study proposed a hybrid method for high-resolution mapping of transport CO₂ emissions in metropolitan regions, and applied it to the Beijing–Tianjin–Hebei (BTH) region of China during 2000-2019. The results indicate that: (1) The transport CO₂ emissions in the BTH region increased rapidly, of which road transport carbon emissions accounting for approximately 80%, air transport carbon emissions accounting for nearly 20%, railway and water transport accounted for a relatively small proportion. (2) For the transport CO₂ emission structure from 2000 to 2019, road transport was still the main source, but its proportion has decreased since recent years, which air transport became the second largest source of emissions and had greater impact on Beijing and Tianjin. (3) The transport carbon emission hot spots were mainly located in Beijing and kept shrinking, while the cold spots were mainly located in the southern part of Hebei Province and kept expanding. (4) The decoupling relationship between county-level transport carbon emissions and economic growth changed from weak decoupling to expansive negative decoupling, showing a non-ideal development in the BTH region. Overall, this study revealed the spatiotemporal characteristics of transport CO₂ emissions in the BTH region, based on which specific carbon reduction strategies could be promoted to facilitate sustainable low-carbon transport development in metropolitan regions in developing countries.

This article analyses actor relationships in Transit Oriented Development (TOD) planning in order to better understand the preconditions necessary for planning processes to result in TOD in lower density contexts, in suburbs, or small cities. Empirically, the analysis builds on a comparative case study of TOD planning projects. The focus in the analytical work is on understanding how market conditions in lower density contexts influence the conditions for TOD planning projects, and how this feeds through to planning processes. The overall conclusion is that we should not expect that planning processes in small cities with low to medium densities of populations and activities differ much from those in more ‘classic’ highly urban TOD locations. Market conditions had an impact on planning processes, but once in the planning stage conditions for implementation depended more on the ability to handle competing interests and less on market conditions. In terms of policy recommendations, it is important for actors to develop a joint vision of the built environment of the site in question that channels organizations’ individual actions in a joint direction. The ability to achieve such a joint vision for the design of the site in question may be more important in small towns than in more ‘typical’ TOD contexts in denser urban areas. This is because all enablers need to work together in a positive way in such location – which may be marginal from a market point of view – for the development to be able to go ahead.

For cities seeking to promote active transport, overcoming the institutional practices of car-centric planning and investment is critical to redistributing funds toward dedicated walking and cycling infrastructure. Slowly, urban policy and research are expanding traditional mobility-centric economic evaluations beyond major road and rail projects. This review paper of the academic literature employs a systematic quantitative literature review (SQLR) methodology and contributes an up-to-date examination of academic economic evaluations undertaken on large-scale active transport infrastructure implementations (i.e. capital costs greater than USD$3 million as of 2022). Seventeen (17) peer-reviewed academic papers were included in the final analysis. Cost-benefit analysis (CBA), followed by cost-effective analysis (CEA) and health impact assessment (HIA), were the most common pre-implementation (ex ante) and post-implementation (ex post) assessment methods. Between implementation-types, contexts, and methodologies, the parameters factored in econometric evaluations present a large degree of variance. Despite this, all studies demonstrated the positive return on investment in large-scale active transport infrastructure, where all CBAs produced benefit-cost ratios greater than the breakeven threshold (i.e. >1). Results show health parameters contribute the greatest benefit to positive evaluations, accounting for 77% of total benefits (and 67% in the CBA papers). However, evaluations inconsistently factor or omit long-term, intergenerational, and non-mobility benefits that highlight a partiality in their approach and can be co-opted to support predetermined outcomes. Further research must seek to establish if more expansive, sustainability-orientated methods are needed, or whether to adopt policy positions acknowledging the positive returns walking and cycling infrastructure deliver.

Walking as one type of physical activity generates benefits for personal health and contributes to sustainability in its environmental, economic, and social dimensions. Based on a cross-sectional survey for a representative sample of German cities with at least 100,000 residents, this study investigates determinants of residents’ walking behavior. Two contexts of promenading in the city for leisure walking and the trip to the supermarket for utilitarian walking are distinguished in order to investigate differences in respondents’ perceived importance of built-environment characteristics and to bridge the gap between the individual level of residents’ behavior and the streetscape level. In addition, the analyses distinguish between frequent and less frequent walkers in order to understand differences in characteristics, behavior, preferences, and perceptions between these two groups. The results of this study with a sample of n = 4,637 respondents show that the relevance of the built environment is higher for leisure walking than for utilitarian walking and higher for frequent walkers compared to less frequent walkers. For leisure walking, “protection”-variables are ranked high (e.g. safety, security), followed by “comfort” (e.g. space, surface quality) and by “delight” (e.g. attractive buildings, greenery). Distance is key for utilitarian walking. Significant differences between frequent and less frequent walkers are identified mainly for the “Delight”-variables, this is attractive buildings and greenery for utilitarian walking, and space availability and street furniture for leisure walking. These differences should be considered in future research and street design practice which might preferably focus on the most demanding person group of frequent walkers.

Equitable access to diverse opportunities for everyone is essential to public transportation. While the mobility for veterinary care visit is pivotal to One Health, pets and their owners often face various barriers in transportation. Despite Hong Kong’s well-received transit-oriented development, pets are strictly prohibited in the major modes of public transport, which is rarely discussed in the literature regarding equitable transportation planning. Therefore, this study examined the variation in Taxi fares to access four different types of veterinary services (general, 24/7, low-cost, and 24/7 low-cost) in Hong Kong using network routing and Geographic Information System. We found that most inaccessible communities to veterinary care mainly include remote rural villages. Moreover, a higher neighborhood household income was associated with a lower Taxi fare to the nearest 24/7 low-cost service in the new growth and rural areas. We further explored several policy recommendations, such as allowing pets on public transport, mobile services, and pet ambulance. Although the effect of travel costs on veterinarian-seeking behavior is inconclusive, this study showcases a novel and holistic examination of transportation barriers to veterinary care through the geographical and financial lens.

E-scooters have exploded in popularity across the United States in recent years. Understanding the effects of shared micromobility on society, as well as understanding how one shared micromobility mode can affect other travel modes is valuable for decision making and evaluation. In this study, the effects of introducing E-scooters on a preexisting bike-sharing system were evaluated using real-world data. A no-ride zone policy for E-scooters around the University of Arizona (UA) effectively created policy-based control and treatment groups to observe the effect of E-scooters on the bike-sharing system. A difference-in-differences regression model was used to estimate the change in the number of bike-sharing trips after the E-scooters were introduced for nonmembers and members, finding that after the introduction of E-scooters, member bike-sharing system trips were decreased by 1.5 trips per station per day in the area where E-scooters were introduced. Furthermore, a temporal and spatial analysis was conducted to evaluate the behavioral change exhibited by bike-sharing users after the introduction of E-scooters. E-scooter data was used to compare the similarity between bike-sharing and E-scooter usage patterns, indicating that E-scooters reduced the number of spontaneous trips taken by bike-sharing users. The number of nonmember bike-sharing trips decreased for all locations, indicating that E-scooters became the more popular option for leisure activities. Furthermore, member bike-sharing system users were found to travel less on weekends than nonmembers.

Despite the development of alternative modes of urban transport, the private car is still the most popular transport option in many regions around the world. Various spatial and socio-economic characteristics of metropolitan areas (MAs) seem to be generally correlated with levels of car use, and thus with car dependency. In this research, we study car dependency in a subgroup of global MAs, that are characterized profiles of car dependency, and are therefore considered outliers. Drawing on data that are available from the Mobility in Cities Database (MCD), we consider 56 MAs and use Mahalanobis distance to identify 7 outlier MAs that are either more, or less car dependent than anticipated by the regression model. We investigate the driving forces behind unpredicted levels of car use and position the outlier MAs in a catalogue of mobility profiles. A combination of urban form, convenience of car use, availability of alternative modes to car and car ownership characteristics were found to contribute to the level of car dependency in these MAs.