Planning and managing intermodal transportation of hazardous materials with capacity selection and congestion

The current literature in the rail–truck intermodal transportation of hazardous materials (hazmat) domain ignores congestion at intermodal yards. We attempt to close that gap by proposing a bi-objective optimization framework for managing hazmat freight that not only considers congestion at intermodal yards, but also determines the appropriate equipment capacity. The proposed framework, i.e., a non-linear MIP and a multi-objective genetic algorithm based solution methodology, is applied to a realistic size problem instance from existing literature. Our analysis indicates that terminal congestion risk is a significant portion of the network risk; and, that policies and tools involving number of cranes, shorter maximum waiting times, and tighter delivery times could have a positive bearing on risk.     

Corridors,hybrids and networks: three global development strategies for high speed rail

After 50 years of experience with high-speed rail (HSR) development in Asia and Europe, there are important lessons that can be derived to inform future efforts to introduce HSR. This paper identifies and explores three strategic models of HSR development: (1) exclusive corridors (e.g., Japan), (2) hybrid networks—both national (e.g., France and Germany) and international (e.g., European Union), and (3) comprehensive national networks (e.g., China and Spain). Evaluations of these models yield outcomes that range from generally positive assessments of the corridor and national hybrid models to more concerns and uncertainties about the international hybrid and comprehensive national network models. When applying these lessons to the United States, contextual differences can make direct applications problematic. At the same time, though, certain elements of these three models that have been proven to be successful elsewhere may be adaptable to the U.S. and other newcomers to HSR development.     

The relative importance of factors that influence the break-even distance of intermodal freight transport systems

The break-even distance of an intermodal freight system is a crucial piece of information for shippers as they decide whether to choose a specific freight transport system. It is also important for policy makers who want to demonstrate to shippers that the intermodal system is substantially more beneficial over a certain distance and encourage shippers to use it. However, the break-even distance is highly dependent on market situations. In other words, it is not possible to estimate the definitive break-even distance that is generally applicable. To date, the literature has addressed factors, including costs and distances, that impact the break-even distance without considering the relative importance of each of these factors. This study attempts to address this gap in knowledge by evaluating the relative importance of geometric and cost factors. The former includes drayage distances (i.e., pre- and post-haulage by trucks), truck-only distance, rail distance, the shape of the market area, and the terminal location, while the latter includes the drayage truck rate, the long-distance truck rate, the rail rate, and the terminal handling rate. Finally, by developing a Monte Carlo-based simulation model, the relative importance can be evaluated. The key finding is that the geometric factors and terminal handling costs are not more significant than the transport costs (i.e., rail costs and long-distance trucking costs) in general. Specifically, to shorten the break-even distance, either reducing the rail rate or increasing the truck rate is the most effective strategy. A 1% change in these factors is almost seven times, three times, and twice as effective as a 1% change in the handling costs at terminals, rail distance, and drayage cost, respectively. Furthermore, neither the oval-shaped market area nor a terminal relocation attracts customers to intermodal systems in general. When two options are combined, the synergic effect is significant.     

Dispatching trucks for drayage operations

We propose a novel model for dispatching trucks given the constraints and sources of uncertainty that arise in drayage operations. The proposed model is designed to minimize the expected cost and is generally applicable to cases including different distributions of random parameters. Numerical examples illustrate this robustness of the model, as well as the potential for reducing the drayage cost by increasing the available storage capacity and permitted number of terminal truck entries. Mathematical results derived within this paper (e.g. expected dwell time) can be used more generally in analyzing transfers in transportation networks under stochastic conditions.     

An ex ante evaluation of mobile depots in cities: A sustainability perspective

Today, a large share of cost, congestion, and emission in cities is attributed to light goods vehicles like carrier vans distributing to the last mile. The aim of many policy agendas is to reach cleaner cities with less disturbance from the distribution vehicles. Several suggestions have been put forward and tested in research and practice, such as access restrictions, multimodal transport, and use of cleaner vehicles. In this paper, we develop a case for a more sustainable freight distribution within cities using an ex ante case study. The idea of the mobile depot is built on the iteration between historical transitions within cities and contemporary developments in urban freight distribution, and then analyzed ex ante both quantitatively in calculations and qualitatively in two stakeholder workshops. The idea is integrated and multimodal, based on a mobile depot (e.g., a bus, truck, barge, or tram) that circles the city and connects to low emission last mile delivery options such as LEVs (Light Electrical Vehicles) or cargo bikes. We found that such a system can be environmentally and socially better for the city context, while maintaining economic viability above a certain utilization rate of the mobile depot for the transport operators.     

Passenger perceptions and the ideal urban bus journey experience

Respondents living close to a Quality Bus Corridor indicated which of 68 items were ‘Things I dislike or things that discourage me from using the bus in Edinburgh’. Eight underlying factors are reported: feeling unsafe (e.g., ‘Drunk people put me off travelling by bus at night’); preference for walking or cycling (e.g., ‘I prefer to walk’); problems with service provision (e.g., ‘No direct route’); unwanted arousal (e.g., ‘The buses are too crowded’); preference for car use (e.g., ‘I feel more in control when I drive’); cost (e.g., ‘The fares are too expensive’); disability and discomfort (e.g., ‘There are not enough hand rails inside the bus’); and self-image (e.g., ‘Travelling by bus does not create the right impression’). The influence of age, gender, household income, car availability and frequency of bus use on factor scores is reported. Analysis of write-in responses extended interpretation to include travelling by bus as a social behaviour in an exchange space and a formulation of the ideal, ‘hassle-free’, urban bus journey as pleasant/deactivated.     

Evaluation of land-use and transport network effects on cyclists' route choices in the Copenhagen Region in value-of-distance space

Growing interest in sustainable transportation systems has driven decision-makers toward policies and investments aimed at promoting cycling, but little to no effort has been made toward incorporating bicycle transport in transport planning models. This study contributes toward this direction by estimating a bicycle route choice model in value-of-distance space from a large sample of 3384 cycling trips that were traced with GPS devices in the Copenhagen Region. The novelty of this study lies in (i) observing cyclists' behavior in a cycling-oriented country, (ii) exploiting rich data about the cycling environment, (iii) estimating the model in value-of-distance rather than preference space, and (iv) not focusing only on preferences for traditional variables (e.g., distance, turns, hilliness, intersections, motorized road characteristics), but also on perceptions and preferences for bicycle facilities (e.g., bicycle lanes, bicycle paths, bicycle traces) and land-use designations (e.g., residential, industrial, sports, scenic areas). The findings from the model show that: (i) cyclists exhibit heterogeneous preferences for avoiding right and left turns, cycling the wrong way, using roundabouts and bridges, and cycling alongside residential and scenic areas; (ii) cyclists dislike cycling on unpaved and hilly surfaces and alongside larger roads; (iii) cyclists have clear perceptions about different types of bicycle facilities, with a preference for bicycle lanes and segregated paths; (iv) cyclists have clear perceptions about land-use designations, with a preference for cycling alongside sports and scenic areas; (v) time-of-day and air temperature contribute to the perceptions of cyclists and their preferences for bicycle facilities and land-use designations.     

Design of international assembly systems and their supply chains under NAFTA

The purpose of this paper is to provide a decision support aid for the strategic design of an assembly system in the international business environment created by NAFTA. The strategic design problem is to prescribe a set of facilities, including their locations, technologies, and capacities, as well as strategic aspects of the supply chain, selecting suppliers; locating distribution centers; planning transportation modes; and allocating target levels (i.e., amounts) for production, assembly, and distribution. The objective is to maximize after-tax profits. This paper presents a mixed integer programming model that represents the complexities of the international design problem as well as relevant enterprise-wide decisions in the US–Mexico business environment under NAFTA. It deals with a broad set of design issues (e.g., bill-of-material restrictions, international financial considerations, and material flow through the entire supply chain) using effective modeling devices (e.g., linearizing non-linearities that arise in modeling transfer prices and allocating transportation charges). Examples demonstrate how managers might use the model as a decision support aid.     

Smartphone gaming is associated with pedestrians' head-turning performances: An observational study of street-crossing behaviors at uncontrolled intersection in Taipei

Pedestrians' head-turning behaviors are crucial to navigating streets safely. This research investigates the effects of phone use on pedestrians' street-crossing behaviors at an uncontrolled intersection where head-turning performances are important to identify a gap among the oncoming traffic. A field study using video cameras was conducted for evaluating pedestrians' head-turning behaviors (e.g., head-turning frequency, not looking at traffic before crossing, looking at the wrong traffic side), crossing time, and sudden movement while they were engaging in various smartphone activities (e.g., calling, texting, gaming, and listening to music). Data such as phone features, distraction types, and personal attributes of the pedestrians were obtained in the interviews conducted after pedestrians had completed crossing the street. The results indicate that the unsafe crossing behaviors (e.g., sudden movement, fewer head-turning frequencies, not looking at traffic before crossing, not looking at left side of traffic first) were more prevalent among those gaming with “Pokemon Go.” Web surfing appears to be the 2nd risky distraction event following gaming with “Pokemon Go.” Logistic regression models reveal several important correlates of unsafe crossing behaviors: being a student, large phone screen (5 in. or larger), and having un-restricted 4G Internet data allowance. The current research recommends that “Pokemon Go” gaming be prohibited while crossing the street.     

Expanding the positive utility of travel through weeklong tracking: Within-person and multi-environment variability of ideal travel time

Travel has been found to have a positive utility—often measured as a desire for non-zero travel time. Although past studies have found that desired travel time varies by trip attributes, they often focused on a single trip purpose (e.g., commute) or single time point (e.g., peak period of one day) and rarely captured variation within individuals and across multiple travel environments. To address these limitations, we employed a smartphone-based travel behavior survey of 186 users making 4397 trips in the Washington, DC, and Blacksburg, VA metropolitan areas. For each user, multiple trips were recorded and the user was asked to repeatedly report on the ideal travel time for each trip. We found that desired travel time varied across different trip environmental characteristics and purposes. Ideal travel time was longer for active travel trips, leisure trips, weekend trips, and when the user conducted activities during trips (e.g., talking, using the phone, looking at the landscape) and traveled with companions. Our study suggests the need for more realistic estimation of the value of travel time savings and the need for quantifying the effect of multitasking during travel on people's willingness to reduce travel time. Practitioners should also consider providing better urban infrastructure for pedestrians and bicyclists to fulfill their trips, as their ideal travel times closely match actual travel times.     

Airport security measures and their influence on enplanement intentions: Responses from leisure travelers attending a Canadian University

Airport security measures can be grouped into two types; standardized screening techniques, which all passengers must undergo (e.g., baggage X-rays, metal detecting scans); and elevated-risk screening (including pat-downs and strip searches) for which only a sub-set of passengers are selected. In the current study, an undergraduate sample (n = 636) was surveyed regarding the professionalism of security screening staff, as well as perceived safety, threat to dignity, and enplanement intentions, following standard and elevated-risk screening measures. Consistent with our hypotheses, perceived professionalism and safety were positively correlated with enplanement intentions, and dignity threat was negatively associated with perceived safety. As the perceived safety from the use of a security measure decreased, enplanement intentions also decreased. Notably, when a screening measure is perceived as having negative consequences (e.g., threatening one's sense of dignity) the safety of the measure is personally invalidated.     

On the estimation of temporal mileage rates

Mathematical and computational techniques are developed for the analysis of annual roadworthiness (MOT) test data that the UK Department for Transport has placed in the public domain. This paper develops a new theory to estimate fine-scale temporal (e.g., monthly) variations in vehicle mileage at a population level – derived from coarse-scale (e.g., annual) mileage data at an individual vehicle level. Numerical time-stepping schemes are derived from the theory and are tested on synthetic data to permit comparison with a known ground-truth mileage rate. Finally, we consider first steps in applying the methods directly to the MOT data set.     

Near “real-time” estimation of excess commuting from open-source data: Evidence from China's megacities

Urban commuting has continuously fascinated scholars and decision-makers. As few people live and work in the same place, there is always excess commuting (i.e., the non-optimal or surplus work travel occurring in cities because people do not minimize their journeys to work for most residents). Traditional commuting data sources (e.g., questionnaires and census surveys) are challenged by small samples, high cost, and low spatiotemporal resolution. In contrast, the big social-sensing data (e.g., smart card and mobile phone data) only consider one or two traffic mode of a route, which is not consistent with the real-life condition. This article proposes a framework for modeling excess commuting based on open-source data of the ten most populous megacities in China. We downloaded residential points of interest (POIs) from Lianjia Real Estate website and obtained workplace POIs from China's AMAP, which is widespread used as Google map. The stratified sampling approach was employed to derive commuting pairs. Both commuting distance and time were obtained by the shortest path under public transportation from AMAP. Then, the linear programming method was employed to calculate the theoretical minimum commuting time and distance of each city. We analyzed the statistical property and spatial distributions of excess commuting and found that (1) commuting distances and time (ranging from 9.1 to18.1 km and from 44.8 to 74.3  minutes) of all ten megacities follow a left-skewed normal distribution; (2) in terms of commute cost, all cities show universal core-periphery patterns where the spatial heterogeneity of the commuting time is more significant than that of distance; (3) for each city, the excess commuting measured by time (i.e. from 0.61 to 0.79) is lower than that measured by distance (i.e. 0.68 to 0.89); and (4) the role of mixing land use, waterbody distribution, and centripetal urbanization on urban commuting distance and time is significant.     

‘Mobility work’: Older adults' experiences using public transportation

This paper contributes to research on public transport accessibility, disabling spaces, and older adult's mobility by highlighting the ‘mobility work’ older adults complete to meet their daily travel needs. Drawing on a systematic and inductive analysis of semi-structured interviews with older adult (65+ years of age) public transit users in Hamilton, Canada, we argue that older adults are faced with mobility work that younger and/or more able-bodied people do not routinely encounter as they meet (or attempt to meet) their daily travel needs using public transportation. Key components of older adults' trips that involve mobility work include walking to and from the bus stop, trip planning, stepping onto/ off of the bus, finding a seat, carrying items on the bus, calling a stop, and travelling in winter conditions. This mobility work can be categorized as physical (e.g., struggling to board the bus), emotional (e.g., worrying about getting a seat), or spatiotemporal (e.g., staying home when the weather is bad). Taken together, this paper puts forward a multidimensional concept of ‘mobility work’ to aid in considering accessibility at the scale of both the individual and the built environment. Further, by highlighting mobility work, this paper demonstrates the ways in which public transport spaces can be disabling for aging bodies and outlines concrete measures public transit agencies can take to make services more accessible to older adult riders.     

Competing risks for train tickets – An empirical investigation of customer behavior and performance in the railway industry

Based on a comprehensive data set of German railway customers we analyze consumers’ choices and particularly subsequent changes of two-part pricing contracts (loyalty cards). In a competing risks framework, we simultaneously estimate effects on three types of contractual events: cancellations, upgrades, and downgrades. Focusing on customer relationship management (CRM) practices, we find several factors affecting these events, some of which railway companies can influence to their advantage. Intuitively, installing auto-renewal procedures for loyalty cards decreases cancellation hazards. However, automated electronic mailings (e.g., reminders and account statements) and advertising (e.g., ticket offers) can be counterproductive and increase the risk of cancellation.     

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).     

Study of the topology and robustness of airline route networks from the complex network approach: a survey and research agenda

Communication via air routes is an important issue in a world organized around a web city network. In this context, the robustness of network infrastructures, e.g. air transport networks, are a central issue in transport geography. Disruption of communication links by intentional causes (e.g., terrorist attack on an airport) or unintentional (e.g., weather inclemency) could be crucial for countries, regions and even the airlines affected themselves. Policymakers and the management of airlines and alliances should be able to reduce the effects of such interruptions in order to ensure good communication through air transport (i.e., maximize the robustness of their network at a reasonable cost). The literature review of the study of air transport route networks through an analysis of complex networks has highlighted a lack of contributions to the study of the topology and the robustness of such networks which contrasts, with advances undertaken for other transport networks or communication systems. This survey suggests areas in which research should be undertaken, based on the existing literature in other areas and from three different perspectives: global route networks, airline alliances, airlines and airports so as to help towards a better understanding of air traffic and, therefore, to be able to assess the potential damage of any airport being inoperative for a continent, country or airline.     

The propensity of business travellers to use low cost airlines

The liberalisation of air transport regulations in the EU has led to the introduction of a number of new airlines serving short haul point to point routes (e.g. easyJet, Ryanair, Debonair, Virgin Express, Go and others). While some of these routes are clearly leisure oriented (e.g. Palma, Ibiza, Venice and Nice), anecdotal evidence suggests that a significant number of travellers are using these services for business related trips. A number of recent studies suggest that pressure is being brought to bear on business travellers to reduce travel expenditure (IATA, 1997. International Air Trasport Association, Press release, No. PS/13/9, 27 January 1997; Bender, A., Stephenson, F., 1998. Journal of Air Trasport Management 4 (2), 99–109; Mason, K.J., 1998. In: Selected Proceedings of the Eighth World Conference on Transport Research (forthcoming)). This paper details a stated preference (SP) survey of European business travellers to assess the propensity for business travellers to use short haul low cost airlines. The study assess the utility placed by travellers on price, airline reward schemes, flight frequency and in-flight comfort service attributes. Price is shown to be the most important purchase factor followed by in-flight comfort and then flight frequency. The study demonstrates the effect of company size on traveller's selection of these utilities.     

Exploring causality in trade and air passenger travel relationships: the case of Asia-Pacific, 1980–2010

This paper explores the potential of heterogeneous Granger analysis in transport geography research by applying this method to a specific case of the often complex and potentially reciprocal linkages between the deployment of transport infrastructures and spatial economic development: the linkages between rising intra-regional volumes of trade and air passenger traffic in Asia-Pacific. Although conceptual and empirical linkages between both indicators can be assumed based on previous research, relatively little is known about the actual causality. Using heterogeneous Time Series Cross Section Granger causality analysis for the period 1980–2010, we explore the presence of four ‘causality scenarios’ amongst different country-pairs: (1) there is no co-evolution, implying that both patterns develop independently (e.g. Japan–Australia); (2) there is ‘real’ co-evolution in that both patterns influence each other through feedback loops (e.g. South Korea–Philippines); (3) air passenger traffic is facilitated by trade (e.g., South Korea–Philippines); or (4) trade is facilitated by air passenger traffic (e.g. Australia–Malaysia). Some tentative interpretations of this heterogeneity are offered.     

Truck movement across the Canada–US border: The effects of 9/11 and other factors

The objective of this study is to isolate the effects of the terrorist attacks of 9/11 and the subsequent stringent border security regime on the levels of truck movement across the Canada–US border. A time series analysis, within an econometric system that rendered stationarity and used the seemingly unrelated regression (SUR) estimator, was performed to model these movements. The analysis represents a natural experiment on the variability of cross-border truck movements in the aftermath of 9/11. Annual truck crossing data over the period 1972–2011, disaggregated by the country of registration (US and Canada) and Canadian jurisdictions (provinces) were used in the analysis. The results indicate that in general, 9/11 have had a negative effect on the cross-border movement of Canadian and US trucks, but the impacts were more pronounced in the case of the US trucks. Other interesting results include an increase in the number of US trucks during the period that followed the last US financial crisis. The results also illustrate the importance of GDP in explaining the observed truck movements across the Canada–US border.