Measuring cycling accessibility in metropolitan areas

Different measures of cycling accessibility have been widely introduced in transportation planning. However, those measurements are mainly restricted by the availability of travel behavior data. In addition, there has been limited comprehensive research on the importance of cycling accessibility to destinations based on the travel time or distance. In this paper, a new index for measuring bikeability in metropolitan areas is introduced. A Cycling Accessibility Index (CAI) is developed for quantifying cycling accessibility within local areas in metropolitan Melbourne, Australia. CAI is defined according to gravity-based measures of accessibility. This index measures cycling accessibility levels in terms of diversity of different land uses, number of activities in statistical areas, and the travel impedance between origins and destinations. The Victorian Integrated Survey of Travel and Activity (VISTA) dataset was used to evaluate the index and investigate the association between the cycling accessibility levels and the number of bicycle trips in local areas. The index is assessed by investigating the association between levels of cycling accessibility and the number of bicycle trips in statistical areas. Key findings indicate that there is a significant positive association between bike trips and the CAI.     

Impacts of high speed rail on railroad network accessibility in China

High speed rail (HSR) is changing the overall travel accessibility of cities in China. There have been a number of studies of high speed rail in China. However, detailed spatiotemporal accessibility pattern of cities affected by the operation of high speed rail in China has not been reported. This study takes a timetable-based accessibility evaluation approach to analyze the changes in travel time, travel cost, and distance accessibility for each of the four main stages of HSR development in China: no HSR service in Stage 1 before August 2008, several HSR lines in Stage 2 between August 2008 and July 2011, reduced operating speed of HSR trains in Stage 3 between August 2011 and November 2012, and addition of new HSR lines and reduction of ticket fares in Stage 4 between December 2012 and January 2013. In addition to the “corridor effect” and the “center-diffusion” pattern, this paper investigates the impacts of HSR on changes in in-vehicle travel time and out-of-vehicle travel time with respect to the policy changes that reduced the operating speed of HSR trains, rearranged the train timetable, and lowered the ticket fare on HSR trains. The analysis results indicate the spatiotemporal pattern of Chinese cities affected by these policy changes. This study is useful for assessing HSR impacts on the accessibility of various cities across China as well as serving as a decision-making support to policies related to adjustments of HSR operation and planning of future HSR routes by considering the existing HSR and non-HSR railway lines.     

The impact of Covid-19 on children's active travel to school in Vietnam

This is among the first studies to provide empirical evidence on active school travel rates and determinants before and after the first Covid-19 lockdown in spring 2020. We have collected and analyzed primary survey data on the school travel patterns of 472 school-age children in Hanoi, Vietnam. The findings show that the Covid-19 pandemic has been quite detrimental: once schools reopened, the prevalence of active school travel decreased from 53% to less than 31%. Where parents, especially mothers, did not face barriers to motorized travel, they assumed the role of chauffeur. Parents who were more concerned about community infections were more motivated to shift children to motorized modes. Walking was more affected than cycling because it was seen as more likely to lead to physical contact and virus transmission. Active school travel dropped more steeply in urban districts (as opposed to poorer, non-urban districts) and in those areas where home-school distances were the largest. It appears that the most common perceptions around barriers to active school travel have been exacerbated during the pandemic as parents and children adapt to “the new normal”.     

Long term effects of an intervention in the outdoor environment—a comparison of older people’s perception in two residential areas,in one of which accessibility improvements were introduced

Walking and participating in activities outdoors in old age can be restricted both by the physical capacity of the individual and by the maintenance and/or the design of the outdoor environment. The purpose of this paper is to compare frequency of walking and frequency of activity outside the home, reported environmental barriers and valuation of the outdoor environment between two areas, in one of which there was an intervention in the outdoor environment 5–8 years prior to this study. The paper is based on a questionnaire sent out in 2011, to all residents 65 years and older in two different areas, the Study Area, an area with an intervention, and the Reference Area. The results show that reports on functional limitations, use of mobility devices and walking difficulties were similar in both areas. Despite that, respondents in the Study Area had a significantly higher frequency of walking and they also participated to a higher degree in activities than respondents in the Reference Area, even though they reported more environmental barriers. The valuation of the outdoor environment was, however, similar in both areas. The results indicate that older people benefit from interventions in the outdoor environment. However, the results also emphasize the importance of good maintenance of the environment.     

Using accessibility measures to integrate land use and transport policy in Edinburgh and the Lothians

To ensure more effective integration of development and transport planning, new national planning policy guidance in the UK requires greater consideration of accessibility issues. Although quantitative accessibility analysis is common in research, the practical application of these techniques in land use planning has been rare, and assessment has been restricted to qualitative considerations. The strong policy focus on accessibility increases the need for robustness, but practical quantitative techniques are still evolving. This paper describes a structured approach to accessibility analysis, as part of the development of a new structure plan for Edinburgh and the Lothians, and demonstrates how an ‘integration index’ can be developed from accessibility measures to help compare alternative approaches.     

A ticket to ride: Evolving landscapes of air travel accessibility in the United States

During the past decade, air passenger service in the United States has been exposed to numerous carrier bankruptcies, antitrust investigations, mergers, labor problems and a massive increase in competition. These internal elements, combined with the rising costs of fuel and the threat of terrorism combine to make a relatively uncertain air travel landscape for both passengers and operators. Moreover, these dynamics have generated significant geographical shifts in airline route structures and airports serviced by commercial carriers. These factors, combined with increasing levels of consumer access to fare and routing information, have altered the landscape of air travel accessibility in the United States. The purpose of this paper is to examine issues of consumer air travel accessibility through an analysis of three critical measures: flight segments, flight time and ticket costs. In addition, a typology of air passenger accessibility is generated for the 156 busiest commercial airports in the United States using these three measures. Results suggest significant local and regional biases in time and cost, relative to distance, for many US markets.     

Visualising where commuting cyclists travel using crowdsourced data

Encouraging more cycling is increasingly seen as an important way to create more sustainable cities and to improve public health. Understanding how cyclists travel and how to encourage cycling requires data; something which has traditionally been lacking. New sources of data are emerging which promise to reveal new insights. In this paper, we use data from the activity tracking app Strava to examine where people in Glasgow cycle and how new forms of data could be utilised to better understand cycling patterns. We propose a method for augmenting the data by comparing the observed link flows to the link flows which would have resulted if people took the shortest route. Comparing these flows gives some expected results, for example, that people like to cycle along the river, as well as some unexpected results, for example, that some routes with cycling infrastructure are avoided by cyclists. This study proposes a practical approach that planners can use for cycling plans with new/emerging cycling data.     

Refugees in Vermont: mobility and acculturation in a new immigrant destination

This paper explores the idea of mobility for recent refugees who have resettled in a non-traditional immigrant destination in the northeastern U.S. It is based on a multi-year qualitative study of travel behavior, preferences, and needs amongst these new arrivals in a small city in the state of Vermont. As a result of their experiences of both forced displacement from their home as well as stasis within camp settings and the refugee determination process, refugees are an example of what some have called “a dialectic of movement/moorings” (Urry, 2003: 125), both on the move and trapped in place. Their resettlement in the U.S., as this paper illustrates, may represent a further extension of this dialectic—placed by government agents in new immigrant reception areas not of their own choosing, forced to commute long distances and into unfamiliar environments for work and limited in their abilities to access healthcare, education and employment (amongst other services) due to a range of transportation barriers. I argue in this paper that refugee mobilities in a new settlement site are about more than inconvenience: barriers to movement may constitute obstacles to acculturation, integration, self-empowerment, and community building.     

Dynamic accessibility mapping using floating car data: a network-constrained density estimation approach

The concept of accessibility has been attracting increasing attention from transportation planners and researchers. The goal of “smart growth” is to promote accessibility rather than mobility. Accessibility mapping is a highly effective tool to support smart growth planning. Studies on accessibility mapping and analysis have proliferated over the last decade as Geographic Information Systems (GIS) has been widely adopted to produce accessibility maps. Nevertheless, a major negative aspect of these efforts is the lack of dynamic access measurement. Traffic conditions change significantly over space and time, leading to non-stationary travel time estimation which is central to accessibility measurement. In this paper, we propose a dynamic accessibility measure based on real-time travel speeds that are derived from floating car data (FCD). We introduce a novel integrated access measure to compute accessibility to Points of Interest (POIs) constrained by road networks. POI accessibility measures are obtained by means of both Network Kernel Density Estimation (NKDE) and Network Linear Density Estimation (NLDE). Therefore, we are able to capture temporal dynamics by taking into account speed variability using FCD during peak and off-peak hours on weekdays and weekends. We demonstrate that the proposed approach can capture the spatio-temporal dynamics of accessibility using FCD for Wuhan city in China. Empirical studies were conducted to examine the impacts of density estimation parameters (search bandwidths) and POI weights on the integrated accessibility. We find that search bandwidth and POI weights would impose profound influence on final accessibility values. Experiments also show that NKDE and NLDE would produce significantly different estimation results.     

Mobility effects of b2c and c2c e-commerce in the Netherlands: a quantitative assessment

For more than a decade researchers have been interested in the implications of e-commerce for personal travel and freight transport. So far it is mostly the mobility effects of business-to-consumer (b2c) e-commerce that have been studied. However, consumer-to-consumer (c2c) e-commerce is becoming popular and may have important implications for mobility as well. Moreover, most studies conducted thus far have looked at the consequences of b2c e-commerce for either personal or freight travel, but not for both.This paper takes a more comprehensive approach. Using a nationwide sample of 3000 Dutch e-shoppers we calculated the potential impacts of both types of e-commerce on personal and freight travel. The results indicated that personal travel in the Netherlands has only marginally decreased as a result of e-shopping, while freight transport has slightly increased. The outcomes showed a net mobility effect, as the reduction in personal travel was not fully compensated by the increase in freight transport. However, this mobility reduction was fully attributed to b2c e-commerce, as c2c e-commerce led to an increase in both personal travel and freight transport.     

Travel difficulties and barriers during later life: Evidence from the National Travel Survey in England

Using data from the National Travel Survey in England, this study investigates which factors lead to experiencing travel difficulties amongst people aged 60 years old and above. The ability to be mobile is one of the key factors enabling older people to maintain their wellbeing and independence while ageing. Given the shift towards an ageing population that our society is experiencing, providing an age-friendly transportation environment becomes necessary to allow older people to be able to fulfil their travel needs and keep involved in societal participation. By employing a conceptual framework based on five interrelated domains shaping mobility during later life, this paper explores older people's difficulties in accessing transport resources, mode usage and undertaking out-of-home activities. Poor health and wellbeing conditions, lack of access to transport resources and gender are identified as the main predictors to experiencing travel difficulties in later life, while activities more affected in this sense are medical appointments, visiting family or friends and social ones. The findings have implications for policies, planning and interventions targeting age-friendly and inclusive transport and environment and show the need to move beyond the transport domain and employ a more holistic and intersectionality-based approach to understand what affects and shapes mobility in later life.     

Market effects of regional high-speed trains on the Svealand line

When the Svealand line in Sweden opened in 1997, it replaced an older railway line between Eskilstuna and Stockholm (a distance of 115 km). Service on the Svealand line is operated with regional high-speed trains. In a case study of the effects of regional high-speed train services, changes in knowledge, valuations and travel behaviour have been analysed. The Svealand line has sparked an increase in regional rail travel of up to seven times compared to the old railway between Eskilstuna and Stockholm. Additionally, the market share has risen from 6% to 30%. Travelling times are valued highly and motorists, particularly, place great value on the high-speed train mode of transport.A general conclusion is that regional high-speed train services have had a major impact on the travel market and on travel behaviour. The improved accessibility to Stockholm, in particular, is especially noticeable among residents living close to the railway stations.     

The indirect effect of the built environment on travel mode choice: A focus on recent movers

Many studies have demonstrated that the built environment has a strong impact on people's travel mode choice. However, the built environment also influences elements such as travel distance and car ownership, which might be the true predictors of which travel modes are chosen. In this study, we analyse the effects of changes in residential neighbourhood on changes in travel mode (for commute trips and leisure trips), both directly and indirectly through changes in car ownership, travel distances and travel attitudes. This study applies a structural equation modelling approach using quasi-longitudinal data from 1650 recently relocated residents in the city of Ghent, Belgium. Results indicate that the built environment has strong direct effects on active leisure trips and car use. However, distance (for car use) and attitudes (for active travel) were found to be important mediating variables. In sum, the effect of the built environment on travel mode choice might be more complex than commonly assumed as it partly seems mediated by travel distance and travel attitudes.     

Non-linear associations between built environment and active travel for working and shopping: An extreme gradient boosting approach

Active travel has environmental, social, and public health-related benefits. Researchers from diverse domains have extensively studied built-environment associations with active travel. However, limited attention has been paid to distinguishing the associations between built environment characteristics at both the origins and destinations and active travel for working and shopping. Scholars have started to examine non-linear associations of built environment with travel behaviour, but active travel has seldom been a focus. Therefore, this study, selecting Xiamen, China, as the case, utilises a state-of-the-art machine learning method (i.e., extreme gradient boosting) to explore the non-linear associations between built environment and active travel for working and shopping. Our findings are as follows. (1) For both purposes, trip characteristics contribute the greatest, and the built environment is also quite important and has larger collective contributions for active travel than does socioeconomics. (2) The relative importance of built environment on active travel for shopping is evidently larger than that for working. (3) All built-environment variables have non-linear associations with active travel, and associations with active travel for working are generally in inverted U or V shapes, while those with shopping trips have much more complex patterns. (4) Differences in the threshold value and gradient exist between built-environment associations with active travel for working and shopping and between variables at origins and destinations. Decision makers are recommended to meticulously disentangle the complex influences of built environment on active travel and distinguish between diverse purposes to make informed and targeted interventions.     

The impacts of high-speed rail extensions on accessibility and spatial equity changes in South Korea from 2004 to 2018

The construction of South Korean High-Speed Rail (HSR) or Korea Train eXpress (KTX) has been evolving in phases since its first operation in 2004. This development raises concerns whether the benefits from the extended HSR network would again be limited to the initial HSR corridors and will deepen the inequalities in accessibility with the rising issue of uneven regional development of the country. This paper measures the accessibility of each stage of HSR network extension and evaluates its spatial distribution, variation, and changes using weighted averaged travel time and potential accessibility indicators. The results of this study find different accessibility impacts from each stage of HSR extension. Although travel-time reduction and increased attractions have been widened in more cities by each HSR extension, the spatial equity is degenerated by the extension in 2010/2011 as the improvement of accessibility has been concentrated in cities along the primary HSR corridor near the already-advantageous Seoul capital area. In contrast, the future HSR extension in 2018 will enhance equitable accessibility to the isolated regions such as the northeast and the southwest regions of the country. However, the relative degree of accessibility improvement will not be large enough for increasing the spatial equity of accessibility without more extended HSR networks between provinces.     

Using GIS to visualise and evaluate student travel behaviour

Using GIS to evaluate travel behaviour is an important technique to increase our understanding of the relationship between accessibility and transport demand. In this paper, the activity space concept was used to identify the nature of participation in activities (or lack of it) amongst a group of students using a 2 day travel-activity diary. Three different indicators such as the number of unique locations visited, average daily distance travelled, and average daily activity duration were used to measure the size of activity spaces. These indicators reflect levels of accessibility, personal mobility, and the extent of participation, respectively. Multiple regression analyses were used to assess the impacts of students socio-economic status and the spatial characteristics of home location. Although no differences were found in the levels of accessibility and the extent of participation measures, home location with respect to a demand responsive transport (DRT) service was found to be the most important determinant of their mobility patterns. Despite being able to travel longer distances, students who live outside of the DRT service area were found to be temporally excluded from some opportunities. Student activity spaces were also visualised within a GIS environment and a spatial analysis was conducted to underpin the evaluation of the performance of the DRT. This approach was also used to identify the activity spaces of individuals that are geographically excluded from the service. Evaluation of these results indicated that although the service currently covers areas of high demand, 90% of the activity spaces remained un-served by the DRT service. Using this data six new routes were designed to meet the coverage goal of public transport based on a measure of network impedance based on inverse activity density. Following assessment of public transport service coverage, the study was extended using a spatial multi criteria evaluation (SMCE) technique to assess the effect of service provision on patronage.     

Incorporating spatial equity into interurban road network design

Methods for the road network design problem, typically, are based on optimization of the network efficiency measures (e.g. network-wide travel time) under a predefined budget. In these approaches, equity issues are not taken into account and, consequently, most of the road improvements are planned next to large cities. Thus, disparities between large and small cities increase, which does not conform to sustainable development objectives. In this paper, to overcome concerns associated with traditional methods, equity is incorporated into the interurban road network design problem. To this end, accessibility concepts are employed. However, unlike previous studies, instead of maximizing the total accessibility, a new definition is proposed for inaccessibility, and total inaccessibility is minimized throughout the network. Using this new definition not only is more compatible with the equity issue, but also helps to eliminate the nonlinearity of the problem. Average travel time to neighboring opportunities is utilized to propose this definition for inaccessibility, which captures the reality more effectively. With the aim of this definition, equity is incorporated into the road network design problem implicitly. This is another improvement over previous methods, where a new term in the objective function or a new constraint is added to include the equity. The proposed model is formulated as a mixed integer linear programming (MILP) problem, where the objective is to minimize the aggregate inaccessibility over all the population centers in the network. To illustrate the application of the model, the Northwest region of the United States is used as the case study. The respective exact solution of the example is found using a commercial solver (CPLEX). This new solution is also compared with the solutions from the traditional methods.     

Spatial analysis of access to and accessibility surrounding train stations: a case study of accessibility for the elderly in Perth,Western Australia

Approximately one-fifth of Perth’s population is aged 60 or older. Projections suggest that this proportion will continue to increase as a result of the large number of children born after the World War II (1946–1964). Access to and accessibility around train stations for the aging population is and will become a more important issue as the elderly population continues to grow. The aim of the paper is to develop and apply a new measure of accessibility to train stations at a fine spatial scale, justified by the special circumstance of the elderly using a case study in Perth, Western Australia. Intercept surveys are used to collect data on factors affecting train station accessibility for patrons aged 60 years or older, at seven highly dispersed train stations. Overall accessibility is measured separately using a composite index based on three travel modes (walk-and-ride, park-and-ride and bus-and-ride). The results illustrate that key variables, such as distance from an origin to a station, walking or driving route directness, land-use diversity, service and facility quality, bus connection to train stations, all affect the accessibility to train stations for the elderly. This implies that improvements to these factors will improve accessibility for this population group.     

Determinants of sustainable mode choice in different socio-cultural contexts: A comparison of Rome and San Francisco

This paper is a part two of a study investigating the relative importance of the built environment, socio-demographic, and attitudinal factors on mode choice. A semi-experimental approach that aims to measure causal effects of the built environment is utilized. This paper reports spatial analysis, survey and modeling results for San Francisco, CA, USA and compares the results with a previous similar study in Rome, Italy. Results reveal that the local street network's integration is important in both cities and that in both cases built environment seems to have higher impact on mode choice than attitudes and socio-demographic factors. Built environment is especially impactful when diversity, design quality, density and syntactical accessibility are combined. In San Francisco willingness to spend time walking, biking or taking transit is lower than in Rome, and residents are more sensitive to concerns about safety and security. Work travel is more affected by demographic and attitudinal factors in San Francisco than in Rome implying that in San Francisco, nonwork travel behavior may have slightly higher potential to respond positively to improvements in the built environment than work trips. In Rome, peer pressure, cost sensitivity, and probiking attitude can compensate for lack of some built environmental characteristics, but not in San Francisco, where only protransit attitude has this effect. Moreover, lack of any built environmental characteristics reduces the possibility of sustainable mode choice more dramatically in San Francisco pointing to the higher importance of investments on improving the built environment rather than marketing efforts to change attitudes.     

全家老小游西藏——和妈妈去西藏

佳佳两岁了。我们给她设计了一次行程：去西藏。青藏铁路线开通，坐上火车去拉萨，对我们大人来说也是一次全新的体验。从北京到拉萨的火车，行程48小时。对于一个两岁的孩子，将是一次耐力与体力的挑战；对于我们，如何带着孩子在火车上度过漫长的48小时也是一次挑战。而到西藏后，孩子会不会闹，会不会不适应，以及西藏的高海拔、低含氧的环境会不会对孩子的健康有影响，都将是我们面临的问题。就这样，我们带着佳佳，带着好奇与不安，忐忑上路了。