Transport planning and the policy-modelling interface

Evidence of the inability of transport models to elucidate policy is cited and reasons for this weakness are then suggested.Attention is drawn to the fundamental changes in both opinion and policy currently taking place. There is less concern with accessibility per se and rather more concern with the provision of adequate or minimum accessibility for certain social groups. More emphasis is placed also on the environmental aspects of transportation.The implications of these changes are outlined. It is not at all clear that the need to adapt and up-date models is appreciated widely enough. Finally, it is considered whether fundamental changes in methodology may help to make transport models more responsive to policy needs.     

Ride Dynamics of Articulated Vehicles-A Literature Survey

This paper presents a review of the available literature describing the methods of modelling the vibrational response of articulated vehicles to the road inputs at the tire contact points. It states and discusses the mathematical techniques that have been put forward for obtaining road input characteristics, for modelling the vehicles in a range of degrees of freedom, and for performing the analysis necessary to obtain the vibrational response. Finally the indices that have been proposed for ride comfort and ride safety are given and the manner in which various researchers relate these to the vibrational characteristics of the vehicles is described.     

Analytical Tire Models for Dynamic Vehicle Simulation

Four basic tire models suitable for dynamic vehicle simulation are formulated. The models are compared through a six-degree-of-freedom nonlinear simulation of a cargo truck crossing rough ground. Guidelines are developed for the selection of an optimum tire model for a given dynamic vehicle simulation.     

Household Mobility Tool Ownership: Modeling Interactions between Cars and Season Tickets

This paper moves beyond traditional models of car ownership in that we propose a framework for modeling household-level decisions to acquire specific types and numbers of mobility tools to fulfill the mobility needs of household members. The framework is applied to a data set collected during the winter and spring of 2000/2001 in the German city Karlsruhe via an interactive web-based stated response survey in which respondents could optimize their household mobility tool sets through on-line feedback concerning the estimated costs of the sets. In our analysis, bivariate ordered probit models are estimated for three combinations of mobility tools: season tickets (i.e., transit passes) and cars, season tickets and small cars and season tickets and large cars. In all instances, strong substitution effects are found – that is, as the number of season tickets increases, the number of cars decreases. This finding underscores the need to move beyond simple models of car ownership to comprehensive models of mobility tool ownership. As demonstrated by our research, failure to do so is likely to lead to biased results.     

A dual control approach for repeated anticipatory traffic control with estimation of network flow sensitivity

This paper investigates a strategic signal control, which anticipates travelers' route choice response and determines signal timings to optimize network‐wide objectives. In general traffic assignment models are used for anticipating this route choice response. However, model‐reality mismatch usually brings suboptimal solutions to the real system. A repeated anticipatory control resolves the suboptimality and addresses the modeling error by learning from information on model bias. This paper extends the repeated control approach and focuses on the estimation of flow sensitivity as well as its influence on control, which is a crucial issue in implementation of model bias correction. The main objective of this paper is first to analyze the estimation error in the real flow derivative that is estimated from noisy measurements. A dual control method is then presented, improving both optimization objective function and derivative estimation during the control process. The proposed dual algorithm is tested on a simple network as well as on a midsize network. Numerical examples confirm the reliable performance of the new reality‐tracking control strategy and its ability to identify (local) optimal solutions on real traffic networks. Copyright © 2016 John Wiley & Sons, Ltd.     

Design of a survey to assess prospects for consumer electric mobility in Canada: a retrospective appraisal

Transportation - This paper reviews the process that led to the development of a national survey instrument used to gather over 20,000 observations across Canada. This survey captured aspects of...     

Calibrating travel time thresholds with cluster analysis and AFC data for passenger reasonable route generation on an urban rail transit network

Transportation - Estimating the route choice patterns for transit passengers is important to improve service reliability. The size and composition of a route choice set affects the choice model...     

基于韧性理论的盾构隧道智能建造北大核心CSCD

以盾构隧道为主的城市轨道交通在"十三五"期间已取得了跨越式的进步,盾构掘进设备在智能化方面取得了飞速发展,但隧道结构设计、结构制造和现场管片拼装的智能化方面,仍需要大的创新与突破。面对建设韧性智慧城市的战略目标,盾构隧道还存在系列问题亟需解决,如对于新材料的物性认识浅、理论少;传感的布置缺乏针对性,监测感知差;隧道管片拼装大量依靠人工,误差大。解决这些问题的关键在于构建一个基于韧性理论的智能化盾构隧道建造系统,通过利用材料和结构的韧性特点,结合计算机等信息技术,采用韧性设计、智能感知、智能制造、智能拼装等一系列措施,使得隧道结构中的材料可智能感知、结构可精准监测、数据可实时孪生、信息可高效管理、制造可自动操控、过程可全域感知、模型可动态调节、管片可智能拼装,最终实现韧性城市的盾构隧道智能化建设。     

A behavioral choice model of the use of car-sharing and ride-sourcing services

There are a number of disruptive mobility services that are increasingly finding their way into the marketplace. Two key examples of such services are car-sharing services and ride-sourcing services. In an effort to better understand the influence of various exogenous socio-economic and demographic variables on the frequency of use of ride-sourcing and car-sharing services, this paper presents a bivariate ordered probit model estimated on a survey data set derived from the 2014–2015 Puget Sound Regional Travel Study. Model estimation results show that users of these services tend to be young, well-educated, higher-income, working individuals residing in higher-density areas. There are significant interaction effects reflecting the influence of children and the built environment on disruptive mobility service usage. The model developed in this paper provides key insights into factors affecting market penetration of these services, and can be integrated in larger travel forecasting model systems to better predict the adoption and use of mobility-on-demand services.     

Identification and quantification of link vulnerability in multi-level public transport networks: a passenger perspective

Robust public transport networks are important, since disruptions decrease the public transport accessibility of areas. Despite this importance, the full passenger impacts of public transport network vulnerability have not yet been considered in science and practice. We have developed a methodology to identify the most vulnerable links in the total, multi-level public transport network and to quantify the societal costs of link vulnerability for these identified links. Contrary to traditional single-level network approaches, we consider the integrated, total multi-level PT network in the identification and quantification of link vulnerability, including PT services on other network levels which remain available once a disturbance occurs. We also incorporate both exposure to large, non-recurrent disturbances and the impacts of these disturbances explicitly when identifying and quantifying link vulnerability. This results in complete and realistic insights into the negative accessibility impacts of disturbances. Our methodology is applied to a case study in the Netherlands, using a dataset containing 2.5 years of disturbance information. Our results show that especially crowded links of the light rail/metro network are vulnerable, due to the combination of relatively high disruption exposure and relatively high passenger flows. The proposed methodology allows quantification of robustness benefits of measures, in addition to the costs of these measures. Showing the value of robustness, our work can support and rationalize the decision-making process of public transport operators and authorities regarding the implementation of robustness measures.