Stated preferences for investigating commuters' diversion propensity

A reasonable response to increasing traffic congestion may come from the rapidly developing traveler information systems. Such systems may be successful if they effectively influence drivers' enroute decisions; in this regard, a critical factor may be commuters' willingness to divert from their regular route in response to information about traffic congestion. This study evaluates the effects of real-time traffic information along with driver attributes, roadway characteristics and situational factors on drivers' willingness to divert.The empirical portion of this study is based on a survey of downtown Chicago automobile commuters. The stated preference approach was used to study commuters' diversion propensity. Drivers expressed a higher willingness to divert if expected delays on their usual route increased, if the congestion was incident-induced as opposed to recurring, if delay information was received from radio traffic reports compared with observing congestion, and if trip direction was home-to-work rather than work-to-home. Respondents were less willing to divert if their alternate route was unfamiliar, unsafe or had several traffic stops. Socioeconomic characteristics were also significant in predicting willingness to divert.     

IRP问题多Agent模型调度策略研究

针对存贮路径问题的复杂特性,运用多Agent技术构建智能模型框架,利用模型中Agent间的协调机制实现存贮路径问题补货策略的求解,同时阐述了调度流程的任务优先级、冲突消除等问题.与集中式数学方法相比,该求解策略更能体现出问题分布式特性,并以一个实例分析验证方法的有效性.     

人文主义理论对双选模式大学英语教学的启示

大学英语教学双向选择模式是在全国大学英语教学改革和大学英语四、六级考试改革不断深化的形势下产生的,它对大学英语教学提出了更高层次的要求,而人文主义教学理论为改革传统教学模式提供了有效的切入口,本文通过阐述人文主义教学理论及其与大学英语教学的关系,总结了人文主义教学理论对双向选择模式下大学英语教学的一些有益启示。     

Distributed coordinated in-vehicle online routing using mixed-strategy congestion game

This study proposes a coordinated online in-vehicle routing mechanism for smart vehicles with real-time information exchange and portable computation capabilities. The proposed coordinated routing mechanism incorporates a discrete choice model to account for drivers’ behavior, and is implemented by a simultaneously-updating distributed algorithm. This study shows the existence of an equilibrium coordinated routing decision for the mixed-strategy routing game and the convergence of the distributed algorithm to the equilibrium routing decision, assuming individual smart vehicles are selfish players seeking to minimize their own travel time. Numerical experiments conducted based on Sioux Falls city network indicate that the proposed distributed algorithm converges quickly under different smart vehicle penetrations, thus it possesses a great potential for online applications. Moreover, the proposed coordinated routing mechanism outperforms traditional independent selfish-routing mechanism; it reduces travel time for both overall system and individual vehicles, which represents the core idea of Intelligent Transportation Systems (ITS).     

Spatial analysis of the competitiveness of the high-speed train and air transport: The role of access to terminals in the Madrid–Barcelona corridor

This paper analyzes the effect of access and egress time to transport terminals over the spatial competiveness of the high-speed train (HST) in the Madrid–Barcelona (Spain) corridor, one of the densest airline domestic markets in the world. Applying spatial data from 2010 provided by a geographical information system (GIS) to a mode choice model estimated with sample travelers in this corridor, the present study examines whether and how the level-of-service of transport terminals spatially affects the competitiveness or modal distribution of HST and air transport in the provinces of Madrid and Barcelona; and, in particular, the degree of competitiveness that can be accrued by the access time provided by private car and transit in different market segments, especially mandatory and leisure trips. In a number of urban zones near train stations and airports, terminal accessibility clearly favors one transport mode in comparison to the other. Improving terminal accessibility via private car or public transit not only affects the relative access to terminals, but also represents a key strategy for readjusting the market shares of the competing modes in the corridor.     

The Green Ship Routing and Scheduling Problem (GSRSP): A conceptual approach

Recent reviews of the literature on ship routing and scheduling note the increased attention to environmental issues. This is an area of paramount importance for international shipping and will be even more so in the future. This short communication is motivated by the increasing attention to ‘green’ routing and scheduling and outlines some possible ways to incorporate the air emissions dimension into maritime transportation OR. The main contribution of this note vis-a-vis the state of the art is that it conceptualizes the formulation of the ‘Green Ship Routing and Scheduling Problem’ (GSRSP) based on existing formulations and highlights all the important parameters of the problem.     

A real-life Multi Depot Multi Period Vehicle Routing Problem with a Heterogeneous Fleet: Formulation and Adaptive Large Neighborhood Search based Matheuristic

In this paper, a new rich Vehicle Routing Problem that could arise in a real life context is introduced and formalized: the Multi Depot Multi Period Vehicle Routing Problem with a Heterogeneous Fleet. The goal of the problem is to minimize the total delivery cost. A heterogeneous fleet composed of vehicles with different capacity, characteristics (i.e. refrigerated vehicles) and hourly costs is considered. A limit on the maximum route duration is imposed. Unlike what happens in classical multi-depot VRP, not every customer may/will be served by all the vehicles or from all the depots. The planning horizon, as in most real life applications, consists of multiple periods, and the period in which each route is performed is a variable of the problem. The set of periods, within the time horizon, in which the delivery may be carried out is known for each customer. A Mixed Integer Programming (MIP) formulation for MDMPVRPHF is presented in this paper, and an Adaptive Large Neighborhood Search (ALNS) based Matheuristic approach is proposed, in which different destroy operators are defined. Computational results, pertaining to realistic instances, which show the effectiveness of the proposed method, are provided.     

The attraction of countryside sites

The distribution of car trips to countryside sites, though primarily dependent upon accessibility, is also a function of the site attraction. This paper describes an attempt to assess attraction in numerical terms drawing upon techniques used by the geographer and the transportation planner. It is based on a behavioural model in which excursion rates and travel times of visitors to countryside sites were obtained by questionnaire surveys in the West Midlands region.

A method is established for determining sequentially the relative attraction of pairs of sites through plotting excursion rate ratios and the respective travel time ratios for common visitor origins; therefrom, for a travel time ratio of unity, the relative excursion rates can be found. Further investigation suggested that site extensiveness contributes to attraction in proportion to the square root of the area. Relative intrinsic attractiveness—essentially land form and mantle—can be determined using a points scoring system. These two components when combined with the accessibility component enables a site distribution factor to be obtained.

The application of distribution factors is demonstrated in relation to an existing attractor system and one origin zone; the effects of the introdction of a new site into this system is postulated; both cases above having real life parallels. Agreement between observed and synthesized excursion rates was within the range ±10 to 20 percent.     

Line haul interstation spacing for low cost feeder modes

The choice behaviour of low cost travel (LCT) modes is very sensitive to travel distance. A line haul system designed on the basis of current planning practice of locating widely spaced stations to cater auto and bus feeder modes with the primary objective of gaining travel speed is hostile to non‐motorized and low cost feeder modes. With the revival of interest in promoting the use of walk'n ride and bike'n ride modes, there is a need to develop an appropriate tool to examine the effect of their specific characteristics in establishing the number and location of stations.

A generic normative behavioural hybrid model for locating the cost minimizing number and location of stations is developed for an LCT‐fed line haul system. The model considers the system with many to many two dimensional line haul demand density function in which the density varies in both x‐ and y‐directions. The feeder mode choice behaviour is incorporated in the model by integrating probability‐access/egress distance function with the objective function. Explicit functional relationships among the parameters of these feeder modes such as modal share as a function of access/egress distance with the parameters of line haul systems are developed. Dynamic programming is used to minimize the system cost. The generic model is shown to collapse into several simplified models capable of yielding approximate solutions for several well known special cases. It has been shown that location of stations is sensitive to the through load on board as well as users’ cost that defines the choice behaviour at large. Numerical examples are presented to demonstrate the applicability of the model.     

The introduction of innovation in Urban transport

More than 200 new systems of transport have been proposed as solutions to problems of urban congestion. However, very few of these have reached even the prototype stage and practically none at all have ever actually been installed.

The author asks himself why this is so. If an invention is to be introduced into a field which is poorly receptive to innovation, it must not only bring something really new and attractive for the users on the functional level as opposed merely to the technological level, but must also consider the political, industrial, social and human context.

The author gives two examples of innovation conceived and developed at the Battelle Geneva Research Centre: one for private transport, a new system for an electric car which will include the interests of the petrol industry, and the other for public transport, the “Speedaway” sponsored by Dunlop Limited. These two systems will be put on the market shortly and will attempt to fulfill the criteria mentioned above.