Public transport accessibility in metropolitan areas: A new approach incorporating population density

Improving public transport accessibility can be considered an effective way of reducing the external costs and negative side effects of motorized commuting. Although there have been many studies conducted that have measured access levels to public transport stops/stations, there has been limited research on measuring accessibility that integrates population density within geographical areas. This study develops a new measure that considers public transport service frequency and population density as an important distributional indicator. A public transport accessibility index (PTAI) is formulated for quantifying accessibility within local areas in metropolitan Melbourne, Australia. A public transport network model is applied to identify the service coverage of public transport modes using a Geographical Information System (GIS). A consistent method is introduced for evaluating public transport accessibility for different levels of analysis, from single elements, including public mode stops to network analysis. The Victorian Integrated Survey of Travel and Activity (VISTA) is used to evaluate the index and examine the association between commuting trips undertaken by public transport and the level of accessibility within the Melbourne metropolitan region. Furthermore, the new index is compared with two existing approaches using the VISTA dataset. Key findings indicate that the PTAI had a stronger association whilst showing more use of public transport in areas with higher values of the PTAI.     

Telecommuting and other trips: an English case study

This paper investigates the importance of non-work travel to the growing population of telecommuters and the implications of this for sustainable travel patterns. Previous research has identified a link between increased online access to work and reduced proximity between residential and workplace locations. These studies raise concerns that as more people split their work activities between home and external workplace, whilst living in more dispersed locations, more unsustainable transport impacts will be generated, including higher vehicle mileage, car dependency, and less physical activity. This paper counters that the implications of telecommuting and other flexible working practices for sustainable travel behaviours may be more dependent upon the number and type of non-work journeys and the accessibility of amenities for these purposes rather than on the distance to the workplace for less frequent commuting journeys. Using the National Travel Survey for England, the travel behaviours of those who identify themselves not as home workers but as working from home at least once a week are compared to other working adults by measuring and modelling the number and purpose of trips within a week's travel diary, independent of distance or mode. Telecommuters record fewer commute trips, more trips for other purposes, and the marginal utility of additional non-work trips to telecommuters is greater than for many other socio-economic characteristics. Thus, addressing the accessibility of non-work destinations proactively through local planning has the potential to optimise the sustainability benefits of telecommuting.     

Geographic heterogeneity in cycling under various weather conditions: evidence from Greater Rotterdam

With its sustainability, health and accessibility benefits, cycling has nowadays been established on research and policy agendas. Notwithstanding the decision to cycle is closely related to local weather conditions and interwoven with the geographical context, research dealing with both aspects is scarce. On the basis of travel diary data, we assess the association of three weather conditions, namely air temperature, wind speed, and precipitation, on cycling trips for leisure and commute purposes for the Greater Rotterdam area, the Netherlands. Besides region-wide logit models and autologistic regressions, place-specific associations of weather conditions are explored through geographically weighted logit models. Considering the entire Rotterdam area, results confirm significant weather effects on cycling while highlighting the necessity to model the residents’ locational component. When the confounding effects of individual and household characteristics are controlled, a key finding is that weather effects appear to vary across space, specifically between the more densely settled central environments and the surrounding lower-density areas. Additionally, the results show differences between leisure and commute trips, in which leisure trips appear to be more weather sensitive and show more pronounced spatial patterns.     

Non-motorized transport and university populations: an analysis of connectivity and network perceptions

This research examines local bicycle and pedestrian networks in the vicinity of the University of Alabama campus to assess the utility of these networks for travel to the university by students and employees. Network connectivity is examined using Geographic Information Systems (GIS) and the results compared to a survey of 3731 university students and employees. Results indicate that areas within one mile of the University of Alabama’s campus have the highest levels of bicycle and pedestrian network connectivity and accessibility. The survey results show that an individual’s positive perception of the bicycle and pedestrian networks is related to their travel behavior, and that this knowledge decreases within an increase in commute distance to campus. Increases in connectivity can be expected to lead to an increase in non-motorized travel, but it is also clear that lack of knowledge of driving and cycling laws is a deterrent to many.     

Thinking regional and acting local: Assessing the joint influence of local and regional accessibility on commute mode in Montreal,Canada

Accessibility indicators, measuring the ease of reaching destinations via a specific mode of transport, are increasingly used in planning and research as they support integrated land use and transport planning. Research has shown that increased local accessibility (walkability for example) is associated with an increase in walking mode share, whereas increase in public transport accessibility is associated with a greater use of public transport. Yet, while public transport agencies are promoting the combination of active and public transport options to address one's diverse mobility needs, local and regional accessibility are rarely addressed together in research or practice. This research aims to determine the joint influence of local and regional accessibility on the transport mode used for work trips in the Montreal metropolitan region, while controlling for socio-demographic characteristics. Data come from the 2013 Origin-Destination survey 2016 Canadian census, 2017 public transport data DMTI Enhanced points of interests. A multinomial logistic model is used to understand how local and regional accessibility are associated with walking, cycling or taking public transport to work across individuals. The results demonstrate that increases in both local and regional accessibility are associated with a higher probability of using sustainable modes. The predicted probabilities suggest that local accessibility is more closely associated with a decrease in car use. This study sheds light on the interaction between local and regional land use and transport systems and is of relevance to planners and policymakers wishing to develop neighborhoods that support the use of sustainable modes.     

Residential dissonance and walking for transport

The concept of residential dissonance contextualizes the combined impact of built environment and individual travel and land-use preferences on travel behavior. A limited number of studies have explored the effect of residential dissonance specifically on walking. However, evidence from the active travel literature suggests that the environmental characteristics associated with diverse active travel modes differ to some extent. This study addresses residential dissonance in a framework specific for walking outcomes, as the applied neighborhood boundaries, residential preferences and the observed built environment were operationalized with measures related to walking for transport. SoftGIS, a public participatory GIS method allowing the mapping of frequently visited destinations was used to survey the daily walking behavior of 772 respondents aged 25–40 years living in the Helsinki metropolitan area, Finland. Ordinal logistic regression analyses were used to assess the adjusted odds of walking a high share of estimated monthly trips and travel distance. The identified residential dissonance groups were found to have significant associations with the walking outcomes. Associations between the observed neighborhood walkability and the walking outcomes varied by trip purpose, being more consistent with walking to utilitarian than to recreational destinations. Overall, the results support views on the interconnectedness of individual attitudes and the built environment in facilitating walking for transport.     

Can the built environment explain gender gap in cycling? An exploration of university students' travel behavior in Toronto,Canada

The benefits of cycling as a healthier and more sustainable transportation alternative to private automobile is emphasized in both literature and policy. One key policy challenge in improving cycling rates is the significant gender gap in cycling that exists across urban regions in North America. In this study, travel behavior of >10,000 students attending four universities in Toronto, Canada, was analyzed to explore gender-based differences in cycling uptake. The mode share for cycling was higher for non-commute trips (9%) when compared to commuting trips to universities (7.6%). In addition, men had higher cycling rates than women, for both commute and non-commute trips. Results from binomial logistic regression models indicate that the built environment-related correlates were different between male and female students, and between commute and non-commute trips. Access to bicycle lanes or cycle tracks was found to increase the odds of female commuter cycling. This effect, however, was moderate in the neighborhoods with higher land use mix. Further, high-speed traffic was a significant barrier to cycling among female commuters. Noticeably, our analysis did not find major gender-based differences in the coefficients relating to travel attitudes and preferences. The findings provide a Canadian comparison to the limited international research on this topic, as well as offer new insights particularly relating to cycling for non-commute trips. The results identify potential avenues for policy intervention regarding the promotion of healthy and sustainable travel behavior among post-secondary students, and more broadly, the millennial generation.     

Representing pedestrian activity in travel demand models: Framework and application

There have long been calls for better pedestrian planning tools within travel demand models, as they have been slow to incorporate the large body of research connecting the built environment and walking behaviors. Most regional travel demand forecasting performed in practice in the US uses four-step travel demand models, despite advances in the development and implementation of activity-based travel demand models. This paper introduces a framework that facilitates the abilities of four-step regional travel models to better represent walking activity, allowing metropolitan planning organizations (MPOs) to implement these advances with minimal changes to existing modeling systems. Specifically, the framework first changes the spatial unit from transportation analysis zones (TAZs) to a finer-grained geography better suited to modeling pedestrian trips. The MPO's existing trip generation models are applied at this spatial unit for all trips. Then, a walk mode choice model is used to identify the subset of all trips made by walking. Trips by other modes are aggregated to the TAZ level and proceed through the remaining steps in the MPO's four-step model. The walk trips are distributed to destinations using a choice modeling approach, thus identifying pedestrian trip origins and destinations. In this paper, a proof-of-concept application is included to demonstrate the framework in successful operation using data from the Portland, Oregon, region. Opportunities for future work include more research on the potential routes between origins and destinations for walk trips, application of the framework in another region, and developing ways the research could be implemented in activity-based modeling systems.     

Is traffic congestion overrated? Examining the highly variable effects of congestion on travel and accessibility

Congestion is universally unpopular, but is it always a problem? Are some places more “congestion-adapted” than others? Using data for Los Angeles, we examine whether the geographies of congestion and accessibility are distinct by mapping and describing them across neighborhoods. We then estimate a series of regression models of trip-making to test the net effects of traffic delays on behavior. We find that there are places where people make many trips and engage in many activities despite lots of congestion, which tend to be more central, built-up areas that host many short trips; in other places, high congestion and low activity coincide. Why the variance? While congestion can constrain mobility and reduce accessibility, traffic is also associated with agglomerations of activity and is thus a byproduct of proximity-based accessibility. Whether agglomeration and congestion have net positive or negative impacts on activity participation thus varies substantially over space. Controlling for factors such as income and working at home, we find that the effects of congestion on access depend on whether congestion-adaptive travel choices (such as walking and making shorter trips to nearby destinations) are viable. Because “congestion-adapted” places tend to host more trip-making, planners may be justified in creating more such places in order to increase accessibility, even if doing so makes absolute levels of congestion worse in the process.     

An approach to imputing destination activities for inclusion in measures of bicycle accessibility

This paper proposes a new method to estimate bicycle accessibility for various trip purposes based on a massive dockless bike-sharing dataset in Shanghai, China. Specifically, a Dirichlet multinomial regression topic model (DMR model) is applied to identify bicycle trajectories' trip purposes, simultaneously considering arrival time and drop-off location. Based on obtained trip purposes, we estimate impedance functions using a negative exponential function. Finally, based on estimated impedance functions, two cases of bicycle accessibility for two different purposes - restaurant and hospital - are presented in Shanghais central area. The results show that almost 90% of bicycle trips are less than 30 min or 5 km. Although the difference between the impedance functions between various trip purposes is not significant, we find that trip purposes of “Work and School” have the highest travel impedance for bicyclists. Cyclists in Shanghai accept longer bicycle travel times for leisure (e.g., shopping) than for commuting (e.g., work or school).     

Does bicycle network level of traffic stress (LTS) explain bicycle travel behavior? Mixed results from an Oregon case study

This paper draws on census data, mode choice, and regional household travel survey data to investigate the relationship between the varying levels of traffic stress (LTS) routes and bicycle travel behavior. Specifically, does bicycle level of traffic stress explain bicycle behavior enough to warrant its use given the limitations? Bicycle level of traffic stress is a new system of bicycle infrastructure classification for cities that cannot afford existing alternatives such as bicycle level of service which is more data-intensive. The LTS criteria lacks many of the input variables found significant in predicting both route choice and mode choice, including several that are required for its more expensive alternatives. The authors select the Salem-Keizer metropolitan area, a case study representative of the kinds of small and medium-sized communities that may prefer to use the LTS to evaluate cycling infrastructure given its lower input costs. The results validate LTS on travel behavior data from the Oregon Household Activity Survey (OHAS), but not mode choice data from the American Community Survey (ACS). These results suggest the LTS criteria may not be useful for cities looking to prioritize infrastructure improvements for specifically increasing commuter cycling. That said, results suggest the system provides a valid measure of a household's propensity to cycle. Further research on a broader cross-section of communities can clarify these mixed results.     

Modeling commuter modal shift from car trips to cycling: Scenario construction and outcomes for Stockholm,Sweden

This article presents the construction and outcomes of scenarios modeling commuter modal shift from car trips to cycling in the metropolitan region of Stockholm, the capital of Sweden. Building and improving upon previous studies in terms of both methodological approach and degree of spatial resolution of the modeling output, we examine scenarios where car commuters able to reach their workplace within 30 and 50 minutes of cycling shift commuting mode. Overall, car–bicycle modal shift figures were 31.6% and 48.7%, respectively. However, there were considerable geographical differences. While a substantial number of new bicycle commuters appeared in all five macro-level subdivisions of the study area, relative modal shift was by far the highest among car commuters living in the Inner City and its immediate surroundings.     

Inequalities in the London bicycle sharing system revisited: impacts of extending the scheme to poorer areas but then doubling prices

Cycling confers transport, health and environmental benefits, and bicycle sharing systems are an increasingly popular means of promoting urban cycling. Following the launch of the London bicycle sharing system (LBSS) in 2010, women and residents of deprived areas were under-represented among initial users. This paper examines how the profile of users has changed across the scheme’s first 3 years, using total-population registration and usage data. We find that women still make fewer than 20% of all ‘registered-use’ LBSS trips, although evidence from elsewhere suggests that the introduction of ‘casual’ use has encouraged a higher overall female share of trips. The proportion of trips by registered users from ‘highly-deprived areas’ (in the top tenth nationally for income deprivation) rose from 6% to 12%. This was due not only to the 2012 LBSS extension to some of London’s poorest areas, but also to a steadily increasing share of trips by residents of highly-deprived areas in the original LBSS zone. Indirect evidence suggests, however, that the twofold increase in LBSS prices in January 2013 has disproportionately discouraged casual-use trips among residents of poorer areas. We conclude that residents in deprived areas can and do use bicycle sharing systems if these are built in their local areas, and may do so progressively more over time, but only if the schemes remain affordable relative to other modes.     

The impacts of the built environment on bicycle-metro transfer trips: A new method to delineate metro catchment area based on people's actual cycling space

Bicycle-metro integration is an efficient method of solving the “last mile” issue around metro stations. Built environment is believed to have a significant effect on cycling behavior. However, transfer cycling around metro stations, as a specific type of cycling behavior, has often been overlooked in transport research. In addition, static contextual units such as circular or street-network buffers are typically used to delineate metro catchment areas of transfer cycling trips. These methods are inaccurate to represent the actual geographic contexts of cycling trips, according to the uncertain geographic context problem (UGCoP). Thus, in this study, bicycle-metro catchment areas are delineated based on aggregating the end points of over three million transfer cycling trips. The impact of the built environment on transfer cycling behavior is also explored.First, we find that the aggregate-points buffer outperforms traditional static buffers in predicting transfer cycling trips. Second, we also identify a high level of spatial heterogeneity in catchment area and transfer cycling density between urban and suburban areas. Third, residential and working population density, bus stop density, and metro stations accessibility have a significant effect on bicycle-metro transfer cycling.     

Do satisfying walking and cycling trips result in more future trips with active travel modes? An exploratory study

Previous studies have indicated that travel satisfaction - the experienced emotions during, and cognitive evaluation of, a trip - can be affected by travel mode choice and other trip characteristics. However, as satisfactory trips might improve a person's attitude towards the used mode, persons may be more likely to use that same mode for future trips of the same kind. Hence, a cyclical process between travel mode choice and travel satisfaction might occur. In this paper we begin to analyse this process—using a structural equation modelling approach on cross-sectional data—for people who engage in walking and cycling for leisure trips in the Belgian city of Ghent. The focus on walking and cycling reflects recent studies indicating that active travel is often associated with the highest levels of travel satisfaction. Results of this exploratory analysis offer tentative support for the idea of a cyclical process: the evaluation of walking and cycling trips positively affects the respondents' attitude towards the respective mode, which in turn has a positive effect on choosing that mode.     

Measuring individuals' travel behaviour by use of a GPS-based smartphone application in Dar es Salaam,Tanzania

A range of mega-cities in the Global South have started to invest in Bus Rapid Transit (BRT) systems, as a complement or replacement for informal paratransit services, in an effort to improve the mobility and accessibility in the city. Yet, few studies have tried to analyse the impact of such systems on the mobility patterns of cities' residents, in part because traditional travel diary surveys are often too expensive to conduct and unsuitable to capture spatial mobility patterns in fast growing cities with a high level of informality in spatial development. In this study, we analyse the applicability of a new method of data collection, i.e. a GPS-based smartphone application, to capture individuals travel behaviour in fast growing mega-cities in the Global South. Our case study is the city of Dar es Salaam (DES) in Tanzania, where the first BRT line is currently being implemented. In our study, the GPS-based app was used by individuals in DES to record distances, departure times and destinations of their trips. Socio-demographic data of respondents were recorded in short questionnaires. The spatial distribution of the trip patterns shows the mobility demand in both high and less connected areas. The results reveal a variation in departure times, travel destinations and trip distances that are one the one hand spatially limited within neighbourhoods and away from the planned BRT, and on the other hand along major roads connecting to the Central Business District (CBD). The short average distances of the trips (<3 km) reveal the characteristics of paratransit modes. The GPS-based smartphone application provides an opportunity to policy makers to engage deeply with the spatial reality of local communities, as a basis for transport investments and policy improvements as steps towards an integrated public transport system.     

Can freeway traffic volume information facilitate urban accessibility assessment?: Case study of the city of St. Louis

In urban contexts, accessibility measures are often utilized to represent the interactions among land use, transport and people’s trips to services and other facilities. Accessibility is generally evaluated using conventional traffic measures such as travel time and distance, but traffic volume, which is a product of the travel trips induced by people’s needs, may also be positively related to accessibility. This study tests the hypothesis “can freeway traffic volume information facilitate urban accessibility assessment?” Traffic volume based accessibility models are proposed to investigate this relationship and test the hypothesis. The results indicate that the answer to this question is a qualified “yes”, as there is a statistically significant relationship between traffic volume differences and accessibility. The coefficients of the models can potentially be used as a reference to guide the urban planning process. The limitations of the proposed models can be addressed by deploying Intelligent Transportation Systems (ITS) traffic sensors on ramps and arterial roadways.     

The path and time efficiency of residents' trips of different purposes with different travel modes: An empirical study in Guangzhou,China

Improving residents' travel efficiency and reducing carbon emissions from travel are the key issues for sustainable development of urban transportation. This study first employed a circuity index to measure the path efficiency of residents' trips based on 2015 survey data in Guangzhou and developed a generalized additive model (GAM) to investigate the relationship between the path efficiency and travel distance for different purposes of trip and different travel modes. On this basis, it further evaluated the time efficiency of different travel modes for each trip. The results showed that there is a complex and nonlinear relationship between the path efficiency and travel distance, which differs between different purposes of trips and different travel modes. In general, trips by non-motorized transport have a lower circuity index and higher path efficiency than those by cars or public transport. Moreover, non-motorized transport is the time-efficiency optimal mode for almost half of the trips, especially for daily shopping trips. However, people prefer to choose public transport on their trips even though public transport is not the time-efficiency optimal mode for these trips. Generally, only about half of the residents chose the time-efficiency optimal mode for their trips. Those who did not choose the time-efficiency optimal mode tended to choose the modes with higher carbon-intensity. The conclusions of this study indicate that for improving travel efficiency and reducing carbon emissions from transport, more efforts should be focused on the non-motorized travel environment and developing relevant policies to encourage more walking and cycling.     

Circuity in urban transit networks

This paper investigates the circuity of transit networks and examines auto mode share as a function of circuity and accessibility to better understand the performance of urban transit systems. We first survey transit circuity in the Minneapolis–St. Paul, Minnesota, region in detail, comparing auto and transit trips. This paper finds that circuity can help to explain mode choices of commuters. We then investigate thirty-five additional metropolitan areas in the United States. The results from these areas show that transit circuity exponentially declines as travel time increases. Moreover, we find that the circuity of transit networks is higher than that of road networks, illustrating how transit systems choose to expand their spatial coverage at the expense of directness and efficiency in public transportation networks. This paper performs a regression analysis that suggests the circuity of transportation networks can estimate transit accessibility, which helps to explain mode share.     

Social inequalities of park accessibility in Shenzhen,China: The role of park quality,transport modes,and hierarchical socioeconomic characteristics

Identifying the geographic units with restricted access to intra-urban parks has become a hot issue in transport studies. Previous literature has examined the social inequalities of park accessibility under the Western context; however, the issue has seldomly investigated against the non-Western background, especially in China. Using a case of Shenzhen (China), this paper examines the accessibility to parks of three quality levels (official standard) under four transport modes (public transit, walking, bicycle, and private car). In particular, the daily travel time from each community (8117) to each park (625) was harvested from the Baidu Map during 18:30–20:30 in July 2016. We further, based on the travel time calculations, develop four baseline indicators (the weighted average, the minimum, the maximum, and the standard deviation travel time) and three tolerance indicators of park accessibility (weighted average travel time within visit tolerance thresholds, standard deviation travel time within visit tolerance thresholds, and number of parks within visit tolerance thresholds) to measure park accessibility for each community. Results show that the seven accessibility indicators generate different estimations and the quantified accessibility varies greatly with park quality levels and transport modes. Communities present greater variations in accessibility to the first quality level and second quality level parks via walking and public transit. In addition, hierarchical regression is utilized to quantify the relationships between park accessibility and sociodemographic characteristics at two geographic levels (community and district). It is found that the associations are subjected to park quality, transport modes, and geographic levels. In particular, we discover significant social inequalities in park accessibility under the mode of public transit, walking, and bicycle. Our study should provide some new insights into accessibility research and advance the understanding of unequal park provision in developing countries.