Modeling travel time reliability of freeways using risk assessment techniques

Travel time reliability is considered to be one of the key indicators for the performance of transport systems and is measured in various ways. This paper synthesizes both reliability concepts: traffic breakdown, the indicator of the instability of travel times, is treated as the risk, whereas travel time variability, the indicator of the uncertainty of travel times, is considered as the consequence of this risk. An analytical formula, using risk assessment technique, explicitly expresses the cost of travel time unreliability as the sum of the products of the consequences (i.e. variability) and the corresponding probabilities of breakdown. It provides a novel measure of travel time reliability and is applicable in network performance evaluations. An empirical example based on a large dataset of freeway traffic flow data from loop detectors shows that the developed travel time reliability measure is both intuitively logical and consistent.     

Risk and reward in public transport contracting

This paper synthesizes evidence from the workshop on risk and reward in public transport contracting. It broadens the usual risk/reward framework to encompass strategic/tactical level issues, identifying high level community goals as the ultimate risk/reward pay-off. The evolution of tactical level public transport planning is reviewed, noting considerable change in functional roles between purchaser and provider in some jurisdictions. No single “best” approach is evident but an emerging interest in relational contracting founded on trust is apparent. Risk allocation between purchaser and provider is considered, a key debate concerning the extent to which providers should be exposed to revenue risk.     

Coordination mechanisms in improving hinterland accessibility: empirical analysis in the port of Rotterdam

Hinterland accessibility is one of the main determinants in port competition. Improving hinterland accessibility is a complex process in which many actors are involved and many factors play a role. It requires coordination mechanisms beyond the price mechanism; conditions of complexity can become such that assistance is needed from other coordination mechanisms, such as introduction of incentives, creation of an interfirm alliance, changing scope, and creating collective action. The goal of this paper is to gain a better understanding on coordination in hinterland chains. Based on the insights of Transaction Cost Economics, a set of variables is explicated in order to understand when, by whom, and under which conditions and situations coordination arrangements are chosen. The variables can be divided into variables related to the complexity of the coordination problem and variables related to the coordination arrangement. The variables are used in an empirical analysis of coordination arrangements in hinterland transport from and to the port of Rotterdam. This analysis provides insight into the patterns and conditions of the emergence of different coordination arrangements that improve hinterland accessibility.     

Transportation education in the United States

Abstract

In the last decade the importance of attitude‐related residential self‐selection has frequently been recognized. In addition people can theoretically self‐select them with respect to other location choices, such as job locations, with respect to travel behaviour, or with respect to the exposure to transport externalities such as noise and congestion. In this paper, we argue that insights into self‐selection processes might significantly improve our knowledge on location choices, travel behaviour and transport externalities. We elaborate on options for self‐selection and briefly formulate methodologies for research into self‐selection.     

Multi-period Research Designs for Identifying Causal Effects of Built Environment Characteristics on Travel Behaviour

Abstract

To date, most empirical studies have applied cross-sectional designs to investigate the relationship between the built environment (BE) and travel behaviour (TB). Since these studies cannot identify causal influence, the use of designs that provide data on multiple moments in time seems necessary. This article classifies these designs and describes how they can be applied to identify causality in this relationship. We recommend the use of natural experiments to assess the impact of changes in land use/infrastructure and prospective longitudinal designs to assess the impact of residential or job moves. In addition, the role of the BE can be explored by assessing the impact of (1) deliberate TB change experiments and (2) changes in household circumstances across different spatial contexts over time. The use of randomised experimental designs is recommended for the former and prospective longitudinal designs for the latter. The article concludes with an outlook on future research.     

Genetic algorithms approach to the problem of the automated vehicle identification equipment locations

The automated vehicle identification (AVI) equipment location problem entails determination of the best locations for the automated vehicle identification equipment. The paper attempts to solve the AVI equipment location problem as a multi‐objective optimization problem, thus determining the best locations on the basis of several criteria. The developed model is based on genetic algorithms. Testing of the model developed on the greater transportation networks is certainly one of the most important directions for the future research, as much as the development of models based on other metaheuristic approaches (Simulated Annealing, Taboo Search). The results obtained in this stage of the research are promising.     

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本文提出一种用于评价公路－铁路联合运输货运枢纽选址方案的整数模型。模型中的四个主体为：货运枢纽经营者、交通运输网络设施规划者、客户、社会公众。介绍了可使全局目标优化的基于主体建模方法(ABM)在货运枢纽选址中的应用。最后，本文以澳大利亚昆士兰州东南部的货物联合运输枢纽为例，介绍了其原始选址过程、个体目标函数测试及基于主体的模型设计过程。     

Long-term impacts of transport infrastructure networks on land-use change: an international review of empirical studies

Improvements in geographical information systems, the wider availability of high-resolution digital data and more sophisticated econometric techniques have all contributed to increasing academic interest and activity in long-term impacts of transport infrastructure networks (TINs) on land use (LU). This paper provides a systematic review of recent empirical evidence from the USA, Europe and East Asia, classified regarding the type of transport infrastructure (road or rail), LU indicator (land cover, population or employment density, development type) and outcome (significance, relationship’s direction) as well as influential exogenous factors. Proximity to the rail network is generally associated with population growth (particularly soon after the development of railway infrastructure), conversion to residential uses and the development of higher residential densities. Meanwhile, proximity to the road network is frequently associated with increases in employment densities as well as the conversion of land to a variety of urban uses including commercial and industrial development. Compared with road infrastructure, the impact of rail infrastructure is often less significant for land cover or population and employment density change. The extent of TINs’ impact on LU over time can be explained by the saturation in TIN-related accessibility and LU development.     

From user equilibrium to system optimum: a literature review on the role of travel information,bounded rationality and non-selfish behaviour at the network and individual levels

Travel information continues to receive significant attention in the field of travel behaviour research, as it is expected to help reduce congestion by directing the network state from a user equilibrium towards a more efficient system optimum. This literature review contributes to the existing literature in at least two ways. First, it considers both the individual perspective and the network perspective when assessing the potential effects of travel information, in contrast to earlier studies. Secondly, it highlights the role of bounded rationality as well as that of non-selfish behaviour in route choice and in response to information, complementing earlier reviews that mostly focused on bounded rationality only. It is concluded that information strategies should be tailor-made to an individual's level of rationality as well as level of selfishness in order to approach system-optimal conditions on the network level. Moreover, initial ideas and future research directions are provided for assessing the potential of travel information in order to improve network efficiency of existing road networks.     

Dockless bike-sharing systems: what are the implications?

ABSTRACT

The emergence of dockless bike-sharing services has revolutionised bike-sharing markets in recent years, and the dramatic growth of shared bike fleets in China, as well as their rapid expansion throughout the world, exceeds prior expectations. An understanding of the impacts of these new dockless bike-sharing systems is of vital importance for system operations, transportation and urban planning research. This paper provides a first overview of the emerging literature on implications of dockless bike-sharing systems for users' travel behaviour, user experience, and relevant social impacts of dockless bike-sharing systems. Our review suggests that the dockless design of bike-sharing systems significantly improves users' experiences at the end of their bike trips. Individuals can instantly switch to a dockless shared bike without the responsibility of returning it back to a designated dock. Additionally, the high flexibility and efficiency of dockless bike-sharing often makes the bike-sharing systems' integration with public transit even tighter than that of traditional public bikes, providing an efficient option for first/last-mile trips. The GPS tracking device embedded in each dockless shared bike enables the unprecedented collection of large-scale riding trajectory data, which allow scholars to analyse people's travel behaviour in new ways. Although many studies have investigated travel satisfaction amongst cyclists, there is a lack of knowledge of the satisfaction with bikeshare trips, including both station-based and dockless bikeshare systems. The availability and usage rates of dockless bike-sharing systems implies that they may seriously impact on individuals' subjective well-being by influencing their satisfaction with their travel experiences, health and social participation, which requires further exploration. The impact of dockless bike-sharing on users' access to services and social activities and the related decreases in social exclusion are also relevant issues about which knowledge is lacking. With the increases in popularity of dockless shared bikes in some cities, issues related to the equity and access and the implications for social exclusion and inequality are also raised.