Travel Options Research Articles

Reconciling Flexibility and Tenure Security for Pastoral Resources: the Geography of Transhumance Networks in Eastern Senegal

The need to maintain or increase livestock mobility in arid Africa has been widely embraced by ecologists, social scientists, and more recently regional governments. These movements are seen to sustain livestock production under a highly variable and changing climate. At the same time, livestock mobility is threatened by the expansion of agriculture onto rangelands. A major conundrum raised in the pastoral development literature is the potential contradiction of the need for spatially-fixed, exclusionary forms of tenure to protect key pastoral resources with the need for socially-porous open systems of resource tenure that ensure flexible access. This has been called the “paradox of pastoral land tenure.” By adopting a transhumance corridor network approach, this paper demonstrates that there is a middle ground where flexible access can be maintained within a fixed network of corridors. A transhumance network includes not only the physical paths or corridors followed by livestock herds but also the encampment sites where livestock pass the night while moving along corridors and the water sources linked to encampment site. This study mapped and characterized 5000 km of corridors, 744 encampments, and 1010 water points in eastern Senegal. These pastoral features form a network of interconnected resources providing alternative options for travel, water, and forage as herds move along a north–south trajectory. The research analyzes spatial variation in the network’s ability to provide these services (water, quality forage, and travel) as influenced by rainfall variability, cropping pressure, and social institutions. Four distinct zones within the study area were compared with analyses showing variation among them in the importance of different factors shaping access. More broadly, the study demonstrates that extant transhumance networks accommodate the competing needs of pastoral tenure security by facilitating herd movements in response to changing resource availabilities through a series of spatially-fixed components (encampment sites, water points, and corridors) that can be recognized and protected through legislation. Thus, the demands for tenure security and flexible patterns of resource use can both be potentially accommodated.

The value of travel time: random utility versus random valuation

This paper identifies, relates and compares two popular modelling approaches to estimate the value of travel time changes. The first (random utility [RU]) assumes that the random component of the model relates to the difference between the utilities of travel options; the second (random valuation [RV]) assumes that it relates to the difference between the value of travel time and a suggested valuation threshold. This paper gives details of the theoretical relationship between the two approaches and compares them empirically at several levels of model sophistication. Datasets from two national studies (the UK and Denmark) are employed. The results show a consistent superiority of the RV approach and a systematic gap in the value of travel time between approaches. A similar pattern across models is found in both countries. This raises questions about the validity of results using the RU approach. The analysis has direct implications for both researchers and policy-makers.

A tabu search heuristic for the heterogeneous vehicle routing problem on a multigraph

We study a time-constrained heterogeneous vehicle routing problem on a multigraph where parallel arcs between pairs of vertices represent different travel options based on criteria such as time, cost, and distance. We formulate the problem as a mixed-integer linear programming model and develop a tabu search heuristic that efficiently addresses computational challenges due to parallel arcs. Numerical experiments show that the heuristic is highly effective and that freight operators can achieve advantages in cost and customer service by considering alternative paths, especially when route duration limits are restrictive and/or when vehicles of smaller capacity are dispatched to serve remote customers.

Modeling Mode Choice of Low-Income Commuters with Sociodemographics, Activity Attributes, and Latent Attitudinal Variables: Case Study in Fushun, China

Low-income residents are dependent on fewer options for travel and have restricted mobility. This study examines the mode choice of low-income commuters based on an activity-based travel survey in Fushun, China. A model of integrated choice and latent variables was utilized to construct and test the significance of sociodemographics, activity attributes, and latent attitudinal variables. More specifically, a “multiple indicators, multiple causes” model was used to construct the latent variables postulated to be important for travel mode choice, and a multinomial logit model was employed to test the significance of explanatory variables. Results indicate that gender, age, and driving license possession play an important role in the formation of these underlying factors: comfort, convenience, reliability, flexibility, safety, and environmental preferences. On several accounts the latent-variable-enriched choice model outperforms the traditional choice model and provides insights into the importance of unobservable variables in the choice process. Preferences for the latent variables except flexibility are found to exert a significant influence on the mode choice of low-income commuters. Reliability is shown to be helpful in increasing the likelihood that low-income commuters will choose public transit. The sociodemographics and activity attributes also have important effects on the choice process. Findings should provide useful information to policy makers and transportation planners to improve the mobility of low-income commuters.

Maintaining Mobility in Substantial Urban Growth Futures

Integrated land use/transport models traditionally follow a simple integration concept: The land use model provides the origins and destinations of trips, and the travel demand model provides aggregate travel times between zones. High levels of congestion and the limitation of travel budgets, however, require travelers to scrutinize travel options and housing locations more carefully. In this paper, a microscopic integration of land use and transport models is proposed that – for the first time – is capable of capturing travel times and constraints at the level of the individual traveler. This level of integration allows choosing housing locations from which workplaces of all household members are accessible. In addition, discretionary travel can be limited to a household's travel budget after mandatory trips have been completed. The model is expected to represent travel and housing location choice constraints more realistically under high congestion/high cost scenarios.

Comparison of Constrained and Ad Hoc Demand-Responsive Transportation Systems

Planning public transport services for areas of low population density is important to enable travel by those without convenient travel options. In such areas, transit vehicles frequently travel with few passengers or even no passengers on board and thereby incur more cost to the transport providers. Demand-responsive transportation (DRT) services are potentially an efficient mobility solution to this problem. The choice of a DRT scheme is important because different types of schemes may produce different performances in the same area with the same demand. Although many DRT schemes have some constraints (for example, a fixed route or fixed time), these impose additional constraints on users who are already constrained, for example, by a lack of access to a car or limited times to undertake activities. Removing the fixed constraint on time leads to evaluating the performance of an ad hoc system. This paper investigates the change in performance of two DRT schemes—a fixed-time but flexible route scheme and a completely ad hoc scheme—by using the multiagent simulation tool, MATSIM, a large-scale agent-based transport simulation, and real data from an existing fixed-time DRT service in rural Victoria, Australia. Experimentation showed that the schemes produced different outcomes for the operator and passengers; however, the optimization algorithm was less important in areas of low demand. Higher levels of demand led to extensive vehicle travel for an ad hoc service, but altering the headways between fixed-time services could achieve a middle ground for operators and passengers. This work is a first step toward developing a decision support tool to evaluate DRT schemes, in particular for those integrated with other modes of transport.

Optimizing a Flexible Mobility on Demand System

This paper analyzes an innovative transportation concept called Flexible Mobility on Demand (FMOD), which provides personalized services to passengers. FMOD is a demand-responsive system: a list of travel options is provided in real-time for each passenger request. The system provides passengers with flexibility to choose from a menu that is optimized in an assortment optimization framework. For operators, there is flexibility in terms of vehicle allocation to service types: taxi, shared taxi, and minibus. The allocation of the available feet to these three services is carried out dynamically and is based on demand and supply so that vehicles can change roles during the day. The FMOD system is built on a choice model that enables it to analyze the consumer surplus. This paper describes the FMOD system and presents simulation results for a network in Tokyo. For FMOD, three models that maximize profit, consumer surplus, or both are considered. FMOD is compared with its counterpart, which does not have flexibility in vehicle allocation under different scenarios. The results show that FMOD improves profit and consumer surplus with a reasonable real-time performance for the considered network.

An online tool for obesity intervention and public health.

BackgroundThough the United States of America (U.S.A.) obesity rate shows signs of leveling off, rates remain high. Poor nutrition contributes to the development of obesity, and physical inactivity is an important cause of numerous diseases and directly linked to obesity. Efforts to improve diet, increase physical activity and pursue other behavioral changes seem imperative. However, the effective management of intervention strategies for large number of participants are challenging because services in primary, secondary, and tertiary cares are often under-resourced, relatively uncoordinated with other parts of the health system. It is thus necessary to have accompanying intervention strategies that can be carried out at population level. In this paper, we describe an online intervention tool designed for the Obesity Prevention Tailored for Health II project to help achieve such goals.ResultsThe first part of the online tool locates healthy food stores and recreational programs within a specified distance of a participant’s home or a place of interest. The food environments include fruit & vegetable stores, farmers’ markets and grocery stores, and the companying popup window shows the street address and contact information of each store. The parks and recreational programs are displayed on names of park or recreational program, types of program available, and city each amenity belongs to. The tool also provides spatial coverage of vegetation greenness, air pollution and of historical traffic accidents involving active travel.The second part of the tool provides optimized travel options for reaching various amenities. By incorporating bicycling, walking and public transit into the trip planner, this online tool helps increase active transport and reduce dependence on automobiles. It promotes transportation that encourages safety awareness, physical activity, health, recreation, and resource conservation.ConclusionsWe developed the first Google-based online intervention tool that assists obese and overweight participants in finding food and recreational amenities around locations of interest and identifying optimized routes that fit their personal preferences. This tool can also serve general public and policy makers for education, disease prevention and health promotion.

Active Transportation by Transit-Dependent and Choice Riders and Potential Displacement of Leisure Physical Activity

Public transit users are expected to have higher levels of active transportation (AT, walking and bicycling) because they often need to walk to and from transit. Surveys in Baltimore and Seattle ( n = 1,622) revealed that transit users performed more AT than nonusers, especially when dependent on transit. Health benefits and impacts of their limited travel options are discussed. Choice transit riders, who use transit and have a car, and dependent transit riders, who are limited to transit use, are compared for differences in AT and leisure physical activity time (LPA). Less LPA is explored as a consequence of the additional AT.

Spatial Filtering for Identifying a Shortest Path Around Obstacles

The shortest path between two locations is crucial for location modeling, spatial analysis, and wayfinding in complex environments. When no transportation system or network exists, continuous space movement adds substantial complexity to identifying a best path as there are increased travel options as well as barriers inhibiting potential movement. To derive the shortest path, various methods have been developed. Recent work has attempted to exploit spatial knowledge and geographic information system functionality, representing significant advantages over existing methods. However, a high density of obstacles increases computational complexity making real‐time solution difficult in some situations. This article presents a spatial filtering method to enhance Euclidean shortest path derivation in complex environments. The new approach offers substantial computational improvement while still guaranteeing an optimal path is found. Application results demonstrate the effectiveness of the approach and its comparative superiority.

A Quantitative and Systematic Methodology to Investigate Energy Consumption Issues in Multimodal Intercity Transportation Systems

Energy issues in transportation systems have garnered increasing attention recently. This study proposes a systematic methodology for policy-makers to minimize energy consumption in multimodal intercity transportation systems considering suppliers’ operational constraints and travelers’ mobility requirements. A bi-level optimization model is developed for this purpose and considers the air, rail, private auto, and transit modes. The upper-level model is a mixed integer nonlinear program aiming to minimize energy consumption subject to transportation suppliers’ operational constraints and traffic demand distribution to paths resulting from the lower-level model. The lower-level model is a linear program seeking to maximize the trip utilities of travelers. The interactions between the multimodal transportation suppliers and intercity traffic demand are considered under the goal of minimizing system energy consumption. The proposed bi-level mixed integer model is relaxed and transformed into a mathematical program with complementarity constraints, and solved using a customized branch-and-bound algorithm. Numerical experiments, conducted using multimodal travel options between Lafayette, Indiana and Washington, D.C. reiterate that shifting traffic demand from private cars to the transit and rail modes significantly reduce energy consumption. Moreover, the proposed methodology provides tools to quantitatively analyze system energy consumption and traffic demand distribution among transportation modes under specific policy instruments. The results illustrate the need to systematically incorporate the interactions among traveler preferences, network structure, and supplier operational schemes to provide policy-makers insights for developing traffic demand shift mechanisms to minimize system energy consumption. Hence, the proposed methodology provide policy-makers the capability to analyze energy consumption in the transportation sector by a holistic approach.

PEDESTRIAN RESPONSE TO ROAD TRAFFIC NOISE FOR MEDIUM SIZE CITY IN INDIA

Level of vehicular noise pollution is one of the major factors to choose pedestrian mode of transportation among other modes of transportation. Transportation systems and their related outcomes are responsible for ensuring safe travel options, including walking people of all ages and different abilities. This study will provide an opportunity to quantify the environmental impact in terms of noise level for future development and planning of pedestrian infrastructure in India. It will also help in modal shifting towards walking, improvements in energy efficiency, and the impact of specific contaminants on health. Exposure of high noise level can cause annoyance and severe stress on auditory and nervous system of pedestrians. Most of the Indian cities have noise level above than acceptable limits because of rapid urbanization with increasing number of vehicular traffic. The objective of this study is to study response of pedestrians towards noise pollution in Roorkee at different locations based on different land use. Roorkee is a medium size city with a population of 2.73 lakhs (Roorkee Metropolitan areas, 2011 census), situated in Uttarakhand, India. It is a city with large number of educational institutions and sizable numbers of student population. Noise level study has been carried out at ten locations on NH-58 near Indian Institute of Technology Roorkee. Noise data was collected at an interval of 30 seconds. Design implications for future improvement of pedestrian infrastructure have been presented in this paper considering traffic noise as an environmental factor. It is expected that the study outcome shall be useful in understanding positive effect of low traffic noise encouraging increased usage of pedestrian facilities within urban transport network.

Sustainable Transportation in Saudi Arabia: Reducing Barriers and Choosing Values

One of the main barriers to achieving a sustainable transportation system in Saudi Arabia is low petrol prices that make public transport an undesirable travel option in the country. The private vehicle is very much a cost-effective means of transportation within the region and will remain so for some time to come. It is very important, therefore, to investigate factors that affect travel behaviour and travel decisions in Saudi Arabia and to investigate attitudes to sustainability in order to devise the right policies to aim for sustainability. It is also important to raise awareness about environmental problems, about the impact of traffic on sustainability and about the role of public transport in achieving this sustainability. The aim of this paper is to investigate the level of awareness of sustainability in Tabuk city in Saudi Arabia and to assess attitudes and preferences towards measures and policies that aim to achieve sustainability. The paper makes a contribution to our understanding of transport attitudes and transport behaviour in Saudi Arabia within the framework of the sustainability issues and with reference to critical gender particularities of the case location.

A New Approach for Reducing Urban Transport Energy

Worldwide, 50% of the population already live in cities, and this percentage is expected to rise. Cities account for an estimated 70% of both energy use and fossil fuel CO2 emissions, and urban passenger travel forms a significant share of this total. This paper introduces a novel approach for reducing both the energy and resulting carbon emissions from such urban travel, in the form of a personal transport energy quota, using a unique cloud technology based intelligent navigation system. The approach has some similarities to the Personal Carbon Trading scheme proposed for the UK some years ago, but is for personal transport only. Like carbon taxes, which have now been introduced in a number of countries/regions, this UK scheme aimed at reducing carbon emissions. The approach proposed in this paper would grant a monthly transport energy quota to all residents. A mobile phone-based application would provide the user with details on the energy costs of each trip, the remaining energy quota at any time, and suggest alternative travel options to minimise trip energy use.

Integrated smartcard solutions: do people want one card for all their services?

Smartcard technologies offer the potential for bringing transport and citizen services onto a single smartcard platform – referred to henceforth as an integrated ‘Transport-Citizen’ (TranCit) card. One question never fully addressed thus far is whether the general public see the integration of services onto a single card as desirable. Based upon research undertaken through the Yorcard project trials, this paper presents the analysis of a series of three focus groups and responses to a public questionnaire which investigated the general desire for multi-application, integrated smartcards. Our findings suggest there is potential for an integrated TranCit card, facilitating easier access to services and travel options across boundaries, even at the international level. A number of operational, technical and data security issues exist which need to be resolved before there would be a greater acceptance of an integrated TranCit card, from both the traveller and the service provider perspective.

Best travel options: Modelling Roman and early-medieval routes in the Netherlands using a multi-proxy approach

During the Roman and early-medieval period in the Netherlands, an extensive network of routes connected settlements on the local, regional and supraregional scale. The orientation of these route networks in part was determined by settlement locations, and in part by environmental factors (e.g. soil type, relief). Therefore these route networks provide a key in understanding the dynamic interplay between cultural and environmental factors.This study focuses on modelling Roman and early-medieval routes using a multi-proxy approach. By combining network friction with archaeological data representing settlements, burial sites and shipping-related finds we wish to investigate the possibilities of using these large-scale datasets for modelling Roman and early-medieval route networks in the Netherlands. Data representing past infrastructure and isolated archaeological finds were used to validate the model output.Results show that in geomorphologically diverse lowland regions, such as the Netherlands, network friction is extremely useful for modelling historical route networks. We found a clear relationship between environmental conditions, settlement locations and the spatial distribution of infrastructure. Using evidence-based modelling, we were able to correctly predict the location of 89% of the currently identified Roman infrastructure, and 85% of the known early-medieval infrastructure in the Netherlands within a 1000m buffer. Additionally, despite only roughly covering a surface area of 13% in the Roman and 11% in the early-medieval period of the Netherlands, 82% and 72% of all known isolated finds were located within the same buffer.

From the concrete to the intangible: understanding the diverse experiences and impacts of new transport infrastructure.

BackgroundChanges to the environment that support active travel have the potential to increase population physical activity. The Cambridgeshire Guided Busway is an example of such an intervention that provides new traffic-free infrastructure for walking, cycling and public transport. This qualitative investigation explored the diverse experiences of new transport infrastructure and its impacts on active travel behaviours.MethodsThirty-eight adult participants from the Commuting and Health in Cambridge natural experimental study were purposively selected according to their demographic and travel behaviour change characteristics and invited to participate in semi-structured interviews between February and June 2013. A mixed-method, following-a-thread approach was used to construct two contrasting vignettes (stories) to which the participants were asked to respond as part of the interviews. Inductive thematic qualitative analysis of the interview data was performed with the aid of QSR NVivo8.ResultsPerceptions of the busway’s attributes were important in shaping responses to it. Some participants rarely considered the new transport infrastructure or described it as unappealing because of its inaccessibility or inconvenient routing. Others located more conveniently for access points experienced the new infrastructure as an attractive travel option. Likewise, the guided buses and adjacent path presented ambiguous spaces which were received in different ways, depending on travel preferences. While new features such as on board internet access or off-road cycling were appreciated, shortcomings such as overcrowded buses or a lack of path lighting were barriers to use. The process of adapting to the environmental change was discussed in terms of planning and trialling new behaviours. The establishment of the busway in commuting patterns appeared to be influenced by whether the anticipated benefits of change were realised.ConclusionsThis study examined the diverse responses to an environmental intervention that may help to explain small or conflicting aggregate effects in quantitative outcome evaluation studies. Place and space features, including accessibility, convenience, pleasantness and safety relative to the alternative options were important for the acceptance of the busway. Our findings show how environmental change supporting active travel and public transport can encourage behaviour change for some people in certain circumstances.

P08 Consumption of alcohol outside the home: Choices for traveling home

BackgroundWhile drinking and driving may be viewed as a failure to act in one׳s best interest, it is acknowledged that a variety of risks and benefits, in addition to biases, are associated with such decisions. This study aimed to evaluate whether residential accessibility (access to amenities and street metrics) and perceived risk impact travel choice and transportation attitudes in the context of drinking alcohol outside one׳s home. MethodsThe data were collected as part of a weekend nighttime roadside survey in nine communities throughout California, U.S.A. in 2012. To be included in the study, drivers had to be at least 16 years of age, able to speak English or Spanish, not in emotional or physical distress, not driving a commercial vehicle, and could understand that they were being asked to voluntarily participate in a research study. To be eligible for the present analysis, respondents reported drinking alcohol in the past year (n=889) and 78% participated in the travel choice survey.For each travel option available the last time they drank alcohol outside the home (excluding the survey night if applicable), participants rated level of service (speed and cost) and attitudes towards each option (convenience and safety). In addition, participants completed a 15-item Alcohol Use Disorder survey and reported on drinking and driving risk perceptions. Hybrid choice modeling (discrete choice with latent variables) was conducted. The likelihood function for a given observation:∫ P (yn | Xn, X⁎; β) f ( I | Xn, X⁎; a) f (X⁎ | Xn; λ) ∂X⁎X⁎Where:P (yn | Xn, X⁎; β)represents the measurement component of choice given explanatory variable and latent construct;f ( I | Xn, X⁎; a)represent the measurement of the latent variable model;f (X⁎; | Xn; λ)represents the structural component of the latent variable model; and∂X⁎the integral of X⁎ and represents the marginal estimates from the joint probability of yn, Ιn, X⁎n. ResultsThe results from the working models indicate that level of service and all of the latent variables (attitudinal constructs) significantly influence choice. When accessibility increases the utility for alternatives to drinking-driver tends to decrease. High binge frequency was positively associated with attitudes towards taxi (p=0.06). Perceptions of risk impacts travel choice indirectly through travel attitudes. ConclusionsThis research highlights an important problem that could be addressed through public health and city and transportation planning efforts.

Downtown, strip centers, and big-box stores: Mode choice by shopping destination type in Davis, California

Growing concerns about climate change and traffic congestion are motivating policymakers to find ways to encourage sustainable travel options. In the United States, where 88 percent of shopping trips are made by car, research identifying the factors that influence shopping mode choice can provide insight into ways to divert some of these trips to more sustainable alternatives. This paper aims to better explain the relationship between the built environment and shopping mode choice by examining how mode choice differs for the same individual across three different types of shopping destinations—downtown, strip center, and big box—in Davis, California. We conducted two cross-sectional online surveys in 2009 and 2010 with a total of 2043 respondents that asked questions about recent shopping. To understand the factors influencing mode choice at these three shopping destination types, we estimate binary logit models for choosing to use an active travel mode (bike or walk) to shop. Our results suggest that while distinct factors influence mode choice at the different destination types, simple infrastructure changes to the destination are not enough to encourage mode shift. Distance to shopping destinations and enjoying bicycling are the primary determinants of choosing active travel modes, while socio-demographic characteristics play a smaller role.

A30 Encouraging active travel to tackle health deprivation in Thurrock communities

Abstract Background The Borough of Thurrock, located in the South East of the UK is one of the most deprived municipalities in the country, despite being only a half hour train journey from London. Personal Travel Planning (PTP) was delivered to nearly every household in Thurrock over the past three-years. Each year, one third of the Borough was targeted for a door-to-door intervention and evaluated for evidence of mode shift towards more sustainable travel. Each year mode shift has been evidenced but in the final year, the eastern part of the Borough was targeted and found to have low car ownership and high deprivation and health inequalities, with a high proportion of elderly and disabled people, and high childhood obesity rates. This is not a typical audience for a PTP programme to create mode shift away from car trips, so some modifications to the approach would be required for it to be effective. Approach described To tailor the intervention to this audience’s needs, we identified an opportunity to intensify promotion of active travel options rather than a shift from car use as such. The result was a 27% increase in walking trips amongst participants, and a 4% increase in walking mode share (based on before and after surveys of travel habits). There was also evidence that some people drastically increased how often they walk, from walking never or very infrequently to walking every day. • This presentation covers two methods used to deliver these Results: Personal Travel Planning using Motivational Interviewing techniques from the health sector • ‘Beat the Street’, a community game to encourage walking, joint-funded with Public Health Structure of presentation The presentation will use multiple sources of evidence including quantitative evaluation tools and qualitative feedback and case studies, and cover the following key points: Background to the Travel Thurrock project, key objectives and challenges • Tailoring the programme to East Thurrock’s unique challenges following two successful years of modal shift from car trips to sustainable modes • Using Motivational Interviewing techniques to deliver mode shift to active travel, and how this is different from typical PTP programmes • Beat the Street and targeting the latent potential for active travel to school • Results, lessons learnt and practical applications for other interventions