Carless in California: Green choice or misery?

Approximately 1 million Californian households do not own a motor vehicle (hereafter a “car”). These households, who are often forgotten in transportation policy discussions, can be organized into two groups based on whether they are voluntarily carless or not. Understanding why some households decide to voluntarily forgo cars could inform policies aiming at reducing our dependency on cars. Understanding the plight of households who are not able to own a car is no less important as these households are at greater risk of social exclusion. Unfortunately, our knowledge of carless households is still sketchy so the purpose of this paper is to start filling this gap. We analyze data from the 2012 California Household Travel Survey using univariate tests and Generalized Structural Equation Models (GSEM) that account for residential self-selection to assess the impacts of various socio-economic and built environment variables on the likelihood to be carless, voluntarily or not. Our results (GSEM Model 1) indicate that carless households are more likely to have less education, a lower income, and a smaller number of members than motorized families. They also tend to live in denser, more land-use diverse, and more walkable areas with better transit coverage. Contrasting voluntarily and involuntarily carless households (GSEM Model 3), we find that involuntarily carless households are less affluent on average and they tend to live in areas that are less land-use diverse, less walkable, and with worse transit coverage. Finally, although residential self-selection is present, its impacts are minor.     

Shelter location and transportation planning under hurricane conditions

This paper develops a scenario-based bilevel programming model to optimize the selection of shelter locations with explicit consideration of a range of possible hurricane events and the evacuation needs under each of those events. A realistic case study for the state of North Carolina is presented. Through the case study, we demonstrate (i) the criticality of considering multiple hurricane scenarios in the location of shelters, and; (ii) the importance of considering the transportation demands of all evacuees when selecting locations for public shelters.     

Job accessibility and the modal mismatch in Detroit

Transportation scholars are challenging traditional formulations of the spatial mismatch hypothesis because previous studies have disregarded the considerable difference between travel modes. This case study of the Detroit metropolitan region uses 2000 census data and a gravity-based model of transportation accessibility to test differences in access to jobs among places and people, and provides support for recent calls for reconceptualizing spatial mismatch. It shows that even though Detroit experiences the greatest distance between African Americans and jobs of any region in the country, most central city neighborhoods offer an advantage in accessibility to jobs compared to most other places in the metropolitan region – as long as a resident has a car. Policies aimed at helping carless people gain access to automobiles may be an effective means of improving the employment outcomes of inner-city residents.     

Car ownership and urban development in Chinese cities: A panel data analysis

Growth in car ownership has significant impacts on the use of urban space and management of urban environments, which makes it a topic of increasing interest especially for developing countries such as China. The dynamics of and factors influencing ownership in Chinese cities need careful investigation. Using fixed effects models applied to annual panel data (1994–2012; 293 cities) this study aimed to achieve the following: 1) assess the relationships between car ownership and average annual income per capita, population, built-up area, road area per capita, urban population density, number of taxis and bus passenger volume; 2) examine the variation of these relationships across geographical regions (East, middle, and West China) and city sizes (cities with small, medium, large, and super-large populations). The results showed that car ownership was positively associated with average annual income per capita, built-up area, road area per capita, urban population density, and number of taxis at the national level. All associations, except with the number of taxis, varied significantly across geographical regions. Built-up area, road area per capita, and number of taxis had different associations with car ownership depending on city sizes. The findings improve the understanding of relationships between car ownership and urban environments vis-a-vis variations in income and infrastructure per capita, population density, and transportation alternatives. These results have important policy implications for managing cars and health problems related to cars in China.     

Host community attitudes toward tourism and cultural tourism development: the case of the Lewes District,southern England

Increasingly research is being conducted on host community attitudes toward tourism. However, few studies have been conducted at a regional level and none have examined the attitudes of the host community towards both tourism and cultural tourism development. This paper outlines a study conducted in the Lewes District of southern England and notes that although residents are generally supportive of tourism development and cultural tourism development, there are differences in opinion concerning the perceived economic and social benefits. In particular, levels of income and proximity to the tourist centre were major influencing factors. Conclusions and recommendations are made concerning the need for tourism planners to distribute the benefits more widely and to engage residents from different socio‐economic groups and localities in tourism planning and development activities. Copyright © 2006 John Wiley & Sons, Ltd.     

Spatiotemporal accessibility to supermarkets using public transit: an interaction potential approach in Cincinnati,Ohio

Improving nutrition in urban regions involves understanding which neighborhoods and populations lack access to stores that sell healthy foods, such as fruits and vegetables. To this end, recent work has focused on mapping regions without access to places like supermarkets, often terming them ‘food deserts’. Until recently, this work has not considered residents’ mobility as facilitated by transportation systems, and even among those that do, few have considered alternative forms of transportation, like public transit, opting for automobile-oriented travel assumptions. This paper analyzes people’s spatio-temporal constraints to accessing supermarkets, and focuses on the transit commuting population. Analysis of commute data from Cincinnati, Ohio shows there are a significant number of residents that have improved access to supermarkets when a grocery shopping trip is made on the way home from work, than if they were to depart from their home location. These results extend previous work showing relatively few automobile commuting residents have better access to supermarkets given their work locations.     

Departure time choice behavior for hurricane evacuation planning: The case of the understudied medically fragile population

Despite the non-trivial number of (non-institutionalized) residents with special needs – referred to as the medically fragile population in this paper – there is virtually no research available to guide the hurricane evacuation planning for this population group. One area is their evacuation time choice behavior that can have tremendous implications for their safety as well as the logistics of the evacuation process. In this paper, we fundamentally advance our understanding of the evacuation timing behavior of this heavily understudied, and potentially vulnerable, population group. Analysis indicates that key differences exist between the medically fragile and non-medically fragile population.     

The impact of local work and residential balance on vehicle miles traveled: A new direct approach

This paper introduces a new approach for explaining the effects of spatial competition for opportunities based on a cumulative opportunities measure of accessibility. We focus on the case of the labor market where some municipalities offer too few workplaces for their local population, forcing some of their residents to long drives. We apply this new accessibility measure to explain households' annual mileage in Switzerland using a Heckman model to account for carless households.We find that car travel demand is much greater in municipalities with a relative undersupply in the local labor market compared to a balanced or oversupplied local labor market. The results show that driving increases with greater distance to the labor market center. The model estimates allow policy makers and planners to quantify as a first assessment the expected average mileage in each municipality for new settlements and to identify municipalities with low expected annual mileage.     

Analysis of ground access modes choice King Khaled International Airport, Riyadh, Saudi Arabia

Airports are vital to the transportation system because air travel is the fastest means of transporting people and goods around the world. Airports also connect aviation systems with other modes of transportation.As a result, access modes to airports are critical to the aviation system, and studying air passenger decisions regarding mode choice is an essential part of airport management and system planning.Though there has been systematic analysis of car use to access airports, there has been less systematic attention to the use of the public transport system, especially the taxi service. The aim of this study is to identify King Khaled International Airport (KKIA) access mode characteristics and users, which has not been investigated previously concentrating on the mix between car and taxi using data collected specifically for this research.More than half (55.5%) of the travelers surveyed arrived at KKIA by private car; taxi and limousine passengers accounted for 42.2% of the sample. The Saudi Public Transit Company (SAPTCO), transported only 2.3% of the air passengers surveyed. These results are similar to findings for an airport in the United States and very different from findings for an airports in the East (e.g., Hong Kong).A binary logit model was developed to evaluate the access mode choice. It was found that income, luggage, travel access time, and nationality significantly affect mode choice.Results provide insight for improved planning of access to KKIA.     

Nonstandard ridehail use in Austin

Ridehailing quickly proliferated by geography and socioeconomic status following the 2012 introduction of UberX and Lyft, but did that proliferation extend to higher-priced, nonstandard-vehicle trips? What explains nonstandard ridehail use, who uses it, and where are they going? RideAustin trip-level data, land-use codes, ACS block groups, and parking data are analyzed using GIS and statistical software to find out. Results imply the nonstandard-vehicle, RideAustin traveler varied from the standard-vehicle traveler in several important socioeconomic ways, including access to a car, household income, race/ethnicity, age, education, and neighborhood trips per capita. About 47% of nonstandard-vehicle trips were made in neighborhoods with the highest carless household rate, and 40% of those were made in SUVs. Better tips and higher star ratings imply standard-vehicle passengers had a higher level of satisfaction compared to nonstandard-vehicle passengers. Policy recommendations are made to incentivize carpooling in these extra-capacity vehicles through subsidies.     

An integrated approach to modeling the impact of floods on emergency services: A case study of Calgary,Alberta

Floods are becoming more frequent and the magnitude of direct consequences, relating to destruction of critical infrastructure and loss of life, has highlighted the importance of flood management. This study proposes a methodology for quantifying the impact of predicted and historic flood events on emergency services. The approach moves beyond simple flood inundation mapping by accounting for the relationship between flood depth and vehicular speed. A case study is presented for Calgary, Alberta, where the depths of a predicted 100-year flood and a historic 2013 flood event are modeled. The methodology applies geographic information systems to flood depth mapping, utilizing digital elevation models, flood extents, and hydrological data. Flood depths are then assigned to links comprising the road network, where the maximum vehicle speed is calculated as a function of the standing depth of water on a link. The flooded network is used to derive service areas for several types of emergency services (emergency medical services (EMS), fire, and police), following targeted response times. The results locate and quantify the residential and work populations that no longer meet the targeted response times. During both flood scenarios, EMS is found to have the greatest reduction in accessibility, with 23% and 47% of residents and workers, respectively, not served. Fire services are seen to be more resilient with only 3% and 9% of residents and workers, respectively, not served. The results for police services are similar to fire services. However, the former have a greater range of response times, meaning these areas represent those that are completely isolated during both flood events. Overall, the integrated methodology quantifies vulnerable populations on a partially degraded network, the results of which can be used to develop evacuation plans and emergency response strategies.     

Assessing the experience of mandated collaborative inter-jurisdictional transport planning in the United States

This paper explores collaborative transport planning among governmental authorities where jurisdictions overlap and the lines of authority are ambiguous or unclear–an increasingly common situation in this era of waning trade and travel restrictions. We do this by examining the experience of mandated collaborative transportation planning among state departments of transportation (DOTs) and metropolitan planning organizations (MPOs) in the USA following a significant change to national surface transportation policy in the early 1990s. To understand how state transport planning and plans changed following the inter-jurisdictional collaboration mandated by passage of the Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA), we examine recent statewide transport planning in 14 of the largest US states and conducted interviews with 66 state and regional planners. We find that, despite the myriad topics that state DOTs tried to include within their comprehensive statewide plans, these plans have had, at best, a limited influence on metropolitan transport planning and activities. Despite this, we find that the mandated collaborative planning did help to increase inter-agency coordination on issues (1) where network or environmental externalities transcend regional boundaries, (2) that require the political clout of a higher-level governmental authority to enforce locally unpopular decisions, or (3) that take advantage of institutional economies of scale.     

The geography of car ownership in Mexico City: a joint model of households’ residential location and car ownership decisions

Suburbanization and car-ownership have increased rapidly in developing-world cities over the past half-century. This study examines the relationship between income, car ownership, and suburbanization across geographies and households in metropolitan Mexico City. Neither car-ownership trends by geography nor a mixed logit model of 43,000 households’ joint car-ownership and residential-location decisions suggest that car ownership and suburbanization are moving hand-in-hand. Instead, wealthier households tend to live in central locations and own and drive cars, while poorer households tend to live further from the urban center and rely more heavily on transit. If a random household’s income doubles, that household is around 44% more likely to get an additional car and 29% more likely to live in the urban center. Given the sticky nature of housing supply and the current model of peripheral housing production, aggregate responses to higher income are more difficult to predict, as they will almost certainly be offset by higher prices. Nevertheless, the findings suggest that higher income and car ownership do not tend to encourage a move to larger houses on larger suburban lots in Mexico City.     

A compact city for the wealthy? Employment accessibility inequalities between occupational classes in the London metropolitan region 2011

The prevalence of gentrification and housing marketisation processes in many cities points to increasingly wealthy inner-city areas and potentially greater population segregation by income. It is plausible that these trends are contributing to regional accessibility inequalities, though quantitative research testing this link is limited. This paper examines differences in employment accessibility between Standard Occupational Classification groups in the London Metropolitan Region for 2011 for car, transit, bus only and walking modes. Additionally, changes in occupational class populations 2006–2016 are considered, revealing continuing inner-city gentrification. Employment accessibility is calculated using cumulative measures, based on travel times from multi-modal network modelling. The results show that while car accessibility is relatively equal between occupational classes, public transport, bus and walk accessibility have significant inequalities favouring professional classes. Low income groups have lower accessibility for the most affordable bus and walk modes, and inequalities are greater for residents in the wider metropolitan region. Furthermore, professional groups combine accessibility advantages with the highest rates of owner occupation, maximising housing wealth benefits. Lower income groups are exposed to rent increases, though this is offset by social housing, which remains the most prevalent tenure in Inner London for low income classes.     

真空管道超高速磁浮交通换乘与安全环境分析

真空管道超高速磁浮交通是未来地面轨道交通发展的重要选择方式,为实现真空管道超高速磁浮交通工程化,需要对乘客换乘真空与常压转换、乘客应急疏散及救援、真空管道散热安全环境进行探索。利用乘客换乘连接通道方案和利用管道内隔离门方案,分析乘客换乘车站内真空与常压的转换设计方案;从地面管道疏散方式和山岭隧道疏散方式方面,探讨真空管道环境的乘客应急疏散及救援方式;从真空管道内超高速磁浮列车车体热平衡、超高速磁浮真空管道系统热平衡方面,研究真空管道超高速磁浮交通换乘散热安全环境,为真空管道超高速磁浮交通换乘与安全环境领域技术突破提供研究依据。     

A GIS-based spatial statistical approach to modeling job accessibility by transportation mode: case study of Columbus,Ohio

Improving job accessibility based on transport connectivity helps to address equity issues. Spatial autocorrelation (SA) is also a focus of interest in transportation planning, but has been neglected in analyzing job accessibility in metropolitan areas. In this study, GIS-based job accessibilities by walking, transit, and car are computed for the metropolitan area of Columbus, Ohio, and three transport-based spatial autoregressive (SAR) models are estimated to account for the SA of job accessibility among neighboring block groups, while controlling for built-environment and socioeconomic factors. SA intensities and extents are compared in order to better understand local spatial clusters of job accessibility across the region. Direct and indirect spillover effects due to an investment change in transportation facilities are estimated and provide important transportation planning information. The results also show that walking-accessed jobs are primarily related to physical settings (e.g., land uses) at the local level. Locations with a higher share of zero-vehicle housing units have better job accessibility by transit. There is a spatial mismatch between Asian population clusters and transit-accessed jobs, possibly because of the car-oriented residential clusters around Honda of America Manufacturing in suburban areas. More importantly, locations with a higher share of single-parent households are at a disadvantage in overall job accessibility. Due to its complex transportation needs, a society friendly to single parents should spatially integrate accessible jobs with other needed activities via land-use and transportation planning. Alternatively, car-ownership programs and non-spatial social supports also might be effective to help secure job opportunities and perform daily life activities.     

Modeling downstream petroleum supply chain: The importance of multi-mode transportation to strategic planning

This paper proposes a deterministic mixed integer linear programming (MILP) model for downstream petroleum supply chain (PSC) network to determine the optimal distribution center (DC) locations, capacities, transportation modes, and transfer volumes. The model minimizes multi-echelon multi-product cost along the refineries, distribution centers, transportation modes and demand nodes. The relationship between strategic planning and multimodal transportation is further elucidated. A case study was considered with real data from the U.S. petroleum industry and transportation networks within Geographic Information System (GIS). A scenario analysis is also conducted to demonstrate the impact of key parameters on PSC decisions and total cost.     

Employment centers and travel behavior: exploring the work commute of Mumbai’s rapidly motorizing middle class

In the Greater Mumbai Region (GMR), jobs and housing are agglomerating in nodes in the periphery of Mumbai City. However, current transportation investments focus on strengthening connections within Mumbai City, while these outlying nodes have received less attention. As housing and jobs move out, given limited travel choices, the need for mobility nudges many middle class Indian households into owning private vehicles. Using household travel survey data from the GMR, this paper develops an understanding of how worker’s trips are different for those who commute to the city versus the exurbs. Socio-economic and transportation indicators for middle class workers going to the city versus the exurbs show that these populations are quite similar demographically. However, those traveling to the exurbs, on average, tend to be at a socio-economic disadvantage with respect to income, education and out-of-pocket travel burdens. Those traveling to exurban work locations have shorter travel times and trip distances, and make much higher use of walking, biking, rickshaws, and motorized two-wheelers compared to commuters to Mumbai City. Across the GMR, car users travel longer and farther compared to motorized two-wheeler users. On average, traveling by a private vehicle is faster than bus or rickshaw travel revealing advantages of private vehicle use. These mode choices in the middle class have resulted in rapid motorization and negative externalities such as traffic congestion and emissions. Evidence of large increases in motorized two-wheelers and cars in India suggests that these modes will likely keep growing, unless competing efficient travel options are supplied.     

Accessibility,mobility, and realized travel behavior: Assessing transport disadvantage from a policy perspective

Limited accessibility and mobility can result in decreased quality of life and well-being, as well as social exclusion. In the United States (U.S.), rural and small urban communities suffer from transport disadvantage due to a lack of transit and a low density of employment, education, recreation, and other opportunities. While the international literature has produced a number of methods and frameworks to assess transport disadvantage and its impacts, the U.S. has lagged behind in providing pertinent studies. The objective of this paper is to establish comprehensive measures that can support the identification, evaluation, and quantification of transport disadvantage in U.S. rural and small urban communities, considering both data availability and the unique characteristics of the U.S. The concept of transport disadvantage in this paper denotes the disadvantage of a specific population group or area that results from a difficulty accessing transportation and/or opportunities. To achieve this objective, this paper develops a spatial multi-perspective approach to account for the three essential elements of transport disadvantage: accessibility, mobility, and realized travel behavior.The developed approach provides an assessment of transport needs and need gaps that can be of benefit to small urban and rural communities and their planning practices, as well as to transport providers. The analysis in this paper suggests that—from a policy perspective—a combination of measures that account for all three essential elements of transport disadvantage should be considered, because the results of each measure complement those of the others. This paper illustrates the proposed approach using a case study of Indiana. The findings suggest that a great part of rural and small urban Indiana presents a low density of opportunities and that transport-disadvantaged residents of such areas might experience the impacts of low transit supply as well. In addition, the findings suggest that residents of rural and small urban areas travel longer distances on their day-to-day activities.This paper attempts to advance the national research pertaining to transport disadvantage and provide a framework that can support planning and policy decisions at the community as well as at the state level.