The potential for real-time passenger information as part of an integrated bus-control/information system

This paper is concerned with the effect of linking innovative bus-control systems with real-time passenger information, with the overall aim of improving conditions for bus operation and passengers in central urban corridors. The first section presents a concise review of bus passenger information systems (particularly their application at bus stops). Then the concept of real-time passenger information is explored. The case for and against real-time information is argued and two British case-studies follow. In the second section it is argued that the provision of real-time information, as part of an integrated bus-control/information system, offers new possibilities for meeting the identified needs of public transport users. Finally, in the third section, some comments are made on the evaluation of different combinations of bus-control and passenger information tested using a simulation method and a series of subjective response surveys. General relationships governing the degree of bus-control required and the extent of information needed are of special interest.     

Towards integrated land use and transportation: A dynamic disequilibrium based microsimulation framework for built space markets

Investigating the factors and processes that influence the spatiotemporal distribution of built space and population in an urban area, plays an extremely important role in our greater understanding of the urban travel behaviour. Existing location of activity centres, especially home and work, strongly influences the short-term individual-level decisions such as mode of transportation, and long-term household-level decisions such as change in job and residential location. Conditions in the built space market also affect households’ and firms’ location and relocation decisions, and hence influence the general travel patterns in an urban area. In this context, this paper addresses a very important, but at the same time, not very widely investigated dimension that plays a key role in the evolution of built space and population distribution: Market. A disequilibrium based microsimulation modelling framework is developed for the built space markets. This framework is then used to operationalize the Greater Toronto and Hamilton Area’s owner-occupied housing market within Integrated Land Use Transportation and Environment (ILUTE) modelling system. Simulation results captured heterogeneity in the transaction prices, due to type of dwellings and different market conditions, in a very disaggregate fashion. The proposed methodology is validated by running the simulation from 1986 to 2006 and comparing the results with the historic data.     

Market segmentation as a mechanism in allowing for variability of traveller behaviour

A major problem with aggregate transport planning models is the accounting of variability in traveller behaviour when the basic unit of analysis is the geographical traffic zone. In an attempt to allow for this variance, recent attention has been given to the role of socio-economic (user and household) characteristics in systematically identifying a homogeneous grouping of travellers with respect to the issue under study rather than restricting the grouping definition according to physical geographical criteria alone. This homogeneous grouping criterion combined eventually with a necessity to represent travel demand in a spatial context, can assist in improving our ability to explain real travel patterns by the development of an improved aggregation condition. The emphasis is on modelling homogeneous groups of travellers separately, and then relating the individual sets of results to each other to obtain an aggregate prediction of behaviour via a knowledge of the representativeness of each group contained in the total sample. This paper presents a technique to identify the relative homogeneity of travellers in accordance with a specified criterion, and illustrates its use with individual household data for the Sydney Metropolitan Area. The paper concludes with a discussion of the advantages of segmentation in operational transport planning, in particular with reference to the aggregation of disaggregate behavioural travel choice models, or movement from a micro-model of individual choice behaviour to an aggregate model of travel demanu.     

An integrated framework for embedding large-scale dynamic traffic assignment models in advanced traveler information systems

In recent years, increasing attention has been drawn to the development of various applications of intelligent transportation systems (ITS), which are credited with the amelioration of traffic conditions in urban and regional environments. Advanced traveler information systems (ATIS) constitute an important element of ITS by providing potential travelers with information on the network's current performance both en-route and pre-trip. In order to tackle the complexity of such systems, derived from the difficulty of providing real-time estimations of current as well as forecasts of future traffic conditions, a series of models and algorithms have been initiated. This paper proposes the development of an integrated framework for real-time ATIS and presents its application on a large-scale network, that of Thessaloniki, Greece, concluding with a discussion on development and implementation challenges as well as on the advantages and limitations of such an effort.     

Towards universal freeway incident detection algorithms

This paper reports the intensive test of the new transport systems centre (TSC) algorithm applied to incident detection on freeways. The TSC algorithm is designed to fulfil the universality expectations of automated incident detection. The algorithm consists of two modules: data processing module and incident detection module. The data processing module is designed to handle specific features of different sites. The Bayesian network based incident detection module is used to store and manage general expert traffic knowledge, and to perform coherent reasoning to detect incidents. The TSC algorithm is tested using 100 field incident data sets obtained from Tullamarine Freeway and South Eastern Freeway in Melbourne, Australia. The performance of the algorithm demonstrates its competitiveness with the best performing neural network algorithm which was developed and tested using the same incident data sets in an early research. Most importantly, both the detection rate and false alarm rate of the TSC algorithm are not sensitive to the incident decision threshold, which greatly improves the stability of incident detection. In addition, a very consistent algorithm performance is achieved when the TSC algorithm is transferred from Southern Expressway of Adelaide to both Tullamarine Freeway and South Eastern Freeway of Melbourne. No substantial algorithm retraining is required. A significant step towards algorithm universality is possible from this research.     

Towards a standardized European road network database

Many Driver Information Systems, especially those that provide location information and route guidance instruction, rely on some form of digital map data, i.e. data that represent the location and other properties of earth-bound objects. A deeperinformation analysis of the data needs of the systems reveals that many needs are very close to the demands that a human navigator makes on a classical paper map. But it also reveals some hidden needs, which relate to the fact that the current Driver Information Systems have only a very poor or no general knowledge. Gathering all these data, putting them into a database and keeping them up to date is an enormous task. Therefore it is very important to know whatsurveying and digitizing techniques are the most suitable for such data. This question is currently being investigated by two DRIVE projects, PANDORA and Task Force EDRM.To guarantee the efficiency of a road network database and to guarantee the exchangeability of traffic messages, a certainstandardization will be inevitable. One possibility is to standardize the finished article, i.e. the map data in the form in which they are represented on the medium used by the system itself (e.g. CD, coded beacon message). This is the solution that has been chosen in Japan, where a CD-ROM based standard has been defined. It is also the solution chosen by the European manufacturers of beacon-supported systems such as Autoguide and LISB, who have defined a standard for the road-vehicle communication link. Another possibility is to standardize the semi-manufactured article, i.e. the map data as they occur in a general purpose road database or in the datafiles produced by data suppliers. This solution has been chosen by Bosch and Philips and had led to their GDF, in which they define a standard data content, a data model and an exhange format for these files. If the systems are going to combine data coming from different sources, the need arises for standard reference numbers. This means that an organizational infrastructure will have to be set up to create and maintain such a reference numbering system. A road database that is kept up to date, represents a lot of money. It will be vitally important for such databases to be legally protected against copying activities.     

Towards a transport policy for the ECOWAS subregion

This paper examines transport policy development in a regional grouping of states whose present transport policies reflect their differing colonial pasts. In addition to locational and physical factors, vested interests in preserving present arrangements, lack of assessment of the repercussions of integration, and lack of political will to surrender to a supra‐national authority decisions which will be binding at the national level are identified as major factors militating against the successful formulation of a common transport policy in West Africa.

It is suggested that, although major changes of policy are often difficult and costly to implement, there is the need to effect institutional changes within the subregion in order to achieve the transport objectives of the ECOWAS treaty.     

Estimation of an integrated driving behavior model

This paper presents the methodology and results of estimation of an integrated driving behavior model that attempts to integrate various driving decisions. The model explains lane changing and acceleration decisions jointly and so, captures inter-dependencies between these behaviors and represents drivers’ planning capabilities. It introduces new models that capture drivers’ choice of a target gap that they intend to use in order to change lanes, and acceleration models that capture drivers’ behavior to facilitate the completion of a desired lane change using the target gap.The parameters of all components of the model are estimated simultaneously with the maximum likelihood method and using detailed vehicle trajectory data collected in a freeway section in Arlington, Virginia. The estimation results are presented and discussed in detail.     

Simulation studies of information propagation in a self-organizing distributed traffic information system

This paper investigates the feasibility of a self-organizing, completely distributed traffic information system based upon vehicle-to-vehicle communication technologies. Unlike centralized traffic information systems, the proposed system does not need public infrastructure investment as a prerequisite for implementation. Due to the complexity of the proposed system, simulation is selected as the primary approach in the feasibility studies. A simulation framework is built based on an existing microscopic traffic simulation model for the simulation studies. The critical questions for building the proposed market-driven system are examined both from communication requirements and traffic engineering points of view. Traffic information propagation both in freeway and arterial networks via information exchange among IVC-equipped vehicles is tested within the simulation framework. Results on the probability of successful IVC and traffic information propagation distance obtained from the simulation studies are generated and analyzed under incident-free and incident conditions for various roadway formats and parameter combinations. Comparisons between the speed of the incident information wave and the speed of the corresponding traffic shock wave due to the incident are analyzed for different scenarios as the most crucial aspect of the information propagation as a potential foundation for application in such a decentralized traffic information system.     

Integrating commuter information needs in the design of a motorist information system

This paper presents the results of a large sample survey designed to investigate the response of commuters to the delivery of traffic information. The main purpose of the survey was to investigate the impact of traffic information on commuters route choices, mode choices, and departure times in order to provide functional requirements for the design of a real-time motorist information system. The surveyed population consisted of 3,893 freeway motorists who routinely commuted to a central business district. The results of the survey indicated that four distinct commuter subgroups existed with respect to their traffic information needs: These groups were: (1) route changers, those willing to change route, or mode before entering the freeway (20.6%), (2) nonchangers, those unwilling to change time, route, or mode (23.4%), (3) time and route changers, (40.1%), and (4) pretrip changers, those willing to change time, mode, or route before leaving the house (15.9%). In terms of receiving traffic information, commercial radio was rated as the most useful and preferred medium both before and while driving. However, only a small, discrete group of commuters were likely to be influenced to change transportation mode. Implication of the survey results for the design of a real-time motorist information system are discussed.     

Bi-objective optimization for the container terminal integrated planning

In this paper, we study the joint optimization of the tactical berth allocation and the tactical yard allocation in container terminals, which typically consist of berth side and yard side operations. The studied two objectives are: (i) the minimization of the violation of the vessels’ expected turnaround time windows with the purpose of meeting the timetables published by shipping liners, and (ii) the minimization of the total yard transportation distance with the aim to lower terminal operational cost. We propose a bi-objective integer program which can comprehensively address the import, export and transshipment tasks in port daily practice. Traditionally, a container transshipment task is performed as a couple of import and export tasks, called indirect-transshipment mode, in which the transit container are needed to be temporally stored in the yard. As the way of transferring containers directly from the incoming vessel to the outgoing vessel, called direct-transshipment mode, has potential to save yard storage resources, the proposed model also incorporates both indirect- and direct-transshipment modes. To produce Pareto solutions efficiently, we devise heuristic approaches. Numerical experiments have been conducted to demonstrate the efficiency of the approaches.     

An optimization model for integrated transit-parking policy planning

The optimization model proposed in this paper is aimed to assist city councils (or other transport authorities) in the planning of integrated transit-parking policies. The objective is to minimize the joint operating deficit of the transit and parking operators while ensuring given minimum levels of (motorized) mobility in a city. The key decision variables are transit fares and parking fees. The impact of price changes on transit and car modal shares are described by logit functions of the generalized travel costs. The practical utility of the model is illustrated with a case study involving a midsize city in Portugal.

     

An integrated, dynamic approach to travel demand forecasting

This paper presents a unified approach for improving travel demand models through the application and extension of supernetwork models of multi-dimensional travel choices. Proposed quite some time ago, supernetwork models solved to stochastic user equilibrium can provide a simultaneous solution to trip generation, distribution, mode choice, and assignment that is consistent with disaggregate models and predicts their aggregate effects. The extension to incorporate the time dimension through the use of dynamic equilibrium assignment methods is proposed as an enhancement that is necessary in order to produce realistic models. A variety of theoretical and practical problems are identified whose solution underlies implementation of this approach. Recommended future research includes improved algorithms for stochastic and dynamic equilibrium assignment, new methods for calibrating assignment models, and the use of Geographic Information Systems (GIS) technology for data and model management.     

国家级综合运输枢纽型城市发展策略研究

以南京市为例,从枢纽型城市整体构建、综合运输通道系统、综合运输枢纽集疏运体系、保障策略四个方面综合提出构建国家级综合运输型城市的发展策略。     

An integrated spatio-temporal GIS toolkit for exploring intra-household interactions

This paper reports on the development of an integrated spatio-temporal GIS toolkit that facilitates the exploration of intra-household interactions. Two tools comprise the toolkit. The first tool, Space-Time Coincidence Analyst, identifies joint activity/travel episodes undertaken by household members. The core of this tool is a set of flexible criteria for classifying episodes as either joint or independent. The second tool, Space-Time Path Visualizer, not only displays space-time paths for household members, but also shows joint episodes undertaken by any two household members together. The toolkit can be applied to any household-based, activity/travel data set so long as required information is specified by the user. To demonstrate its usefulness for research, the toolkit is applied to the TAPS (Toronto Activity Panel Survey) 2002–03 data set. The results suggest that considerable variation exists in the number of joint activity/travel episodes identified using different classification criteria. Specifically, when using restrictive criteria (i.e., same timing, specific activity type/travel mode), only 2,265 joint activity/travel episodes are identified compared to 8,791 when using more flexible criteria. In turn, our results show that certain key attributes for independent and joint activity/travel episodes (i.e., frequency per household, starting time, ending time and duration) also vary under the different classification criteria.

推进武汉综合交通跨越式发展

从全国来看,当前交通工作存在的突出问题主要表现为"一个不适应"和"五个落后于";就武汉交通而言,交通建设发展主要表现为"三个不平衡",即重点项目建设的发展不平衡,港航站场建设的发展不平衡,农村公路建设的发展不平衡;行业管理工作存在"三个相对滞后",即中心城区运输管理体制改革相对滞后,农村公路养护管理相对滞后,道路客运和城市公交城乡结合部有机衔接相对滞后.     

Towards marginal cost pricing: A comparison of alternative pricing systems

European urban areas are marred by the problems of congestion and environmental degradation due to the prevailing levels of car use. Strong arguments have thus been put forward in support of a policy based on marginal cost pricing (European Commission 1996). Such policy measures – which would force private consumers to pay for a public service that was previously provided "for free" – are, however, notoriously unpopular with the general public and hence also with their elected representatives – the politicians. There is thus an obvious tension between economic theory, which suggests that marginal cost pricing is the welfare maximising solution to urban transport problems, and practical experience, which suggests that such pricing measures are unwanted by the affected population and hence hard to implement through democratic processes. The AFFORD Project for the European Commission has aimed to investigate this paradox and its possible solutions, through a combination of economic analysis, predictive modelling, attitudinal surveys, and an assessment of fiscal and financial measures within a number of case study cities in Europe. In this paper the methodology and results obtained for the Edinburgh case study are reported in detail. The study analyses alternative road pricing instruments and compares their performance against the theoretical first best situation. It discusses the effect of coverage, location, charging mechanism and interaction with other instruments. The paper shows that limited coverage in one mode may lead to a deviation from the user pays principle in other modes, that location is as important as charge levels and that assumptions about the use of revenues are critical in determining the effect on equity and acceptability. Finally the results show that a relatively simple smart card system can come close to providing the economic first best solution, but that this result should be viewed in the context of the model assumptions.