The effects of in-vehicle tasks and time-gap selection while reclaiming control from adaptive cruise control (ACC) with bus simulator

This research aimed to find out the effects of in-vehicle distractions and time-gap settings with a fix-based bus driving simulator in a following scenario. Professional bus drivers were recruited to perform in-vehicle tasks while driving with adaptive cruise control (ACC) of changeable time-gap settings in freeway traffic. Thirty subjects were divided equally into three groups for different in-vehicle task modes (between subjects), including no task distraction, hands-free, and manual modes. Further, time-gap settings for the experimental ACC were: shorter than 1.0 s, 1.0–1.5 s, 1.5–2.0 s, and longer than 2.0 s (within subjects). Longitudinal (mean headway, forward collision rate, and response time) and lateral control (mean lateral lane position and its standard deviation) performance was assessed. In the results, longitudinal control performance was worsened by both shorter time-gaps and heavier in-vehicle tasks. But the interaction indicated that the harm by heavier in-vehicle distraction could be improved by longer time-gaps. As for the lateral control, it would only be negatively affected by shorter time-gap settings. This research indicates the effects of time-gaps and in-vehicle distraction, as well as the interaction. Proper time-gap selection under different in-vehicle distractions can help avoid accidents and keep safe.     

Simulation of safety: A review of the state of the art in road safety simulation modelling

Recent decades have seen considerable growth in computer capabilities, data collection technology and communication mediums. This growth has had considerable impact on our ability to replicate driver behaviour and understand the processes involved in failures in the traffic system. From time to time it is necessary to assess the level of development as a basis of determining how far we have come. This paper sets out to assess the state of the art in the use of computer models to simulate and assess the level of safety in existing and future traffic systems. It reviews developments in the area of road safety simulation models. In particular, it reviews computer models of driver and vehicle behaviour within a road context. It focuses on stochastic numerical models of traffic behaviour and how reliable these are in estimating levels of safety on the traffic network. Models of this type are commonly used in the assessment of traffic systems for capacity, delay and general performance. Adding safety to this assessment regime may allow more comprehensive assessment of future traffic systems. To date the models have focused primarily on vehicular traffic that is, cars and heavy vehicles. It has been shown that these models have potential in measuring the level of conflict on parts of the network and the measure of conflict correlated well with crash statistics. Interest in the prediction of crashes and crash severity is growing and new models are focusing on the continuum of general traffic conditions, conflict, severe conflict, crash and severe crashes. The paper also explores the general data types used to develop, calibrate and validate these models. Recent technological development in in-vehicle data collection, driver simulators and machine learning offers considerable potential for improving the behavioural base, rigour and application of road safety simulation models. The paper closes with some indication of areas of future development.     

Management of traffic congestion in adaptive traffic signals using a novel classification-based approach

Traffic congestion is a critical problem which makes roads busy. Traffic congestion challenges traffic flow in urban areas. A growing urban area creates complex traffic problems in daily life. Congestion phenomena cannot be resolved only by applying physical constructs such as building bridges and motorways and increasing road capacity. It is necessary to build technological systems for transportation management to control the traffic phenomenon. In this article, a new idea is proposed to tackle traffic congestion with the aid of machine learning approaches. A new strategy based on a tree-like configuration (i.e. a decision-making model) is suggested to handle traffic congestion at intersections using adaptive traffic signals. Different traffic networks with different sizes, varying from nine to 400 intersections, are examined. Numerical results and discussion are presented to prove the efficiency and application of the proposed strategy to alleviate traffic congestion.     

Using global positioning system for bus priority in London: traffic signals close to bus stops

London's bus network is one of the largest and most comprehensive urban transport systems in the world. The contribution of buses is recognised by implementing a series of initiatives including bus priority at traffic signals. London has a long history of the implementation of bus priority at traffic signals. It has kept pace with the development of new technologies by updating its bus priority system. Now, London is moving towards a bus management system based on global positioning system (GPS), which will also be used to provide bus priority at traffic signals. The authors describe theoretical work carried out by TRG on behalf of Transport for London Bus Priority Team to tackle the challenge posed by locational error associated with GPS where a traffic signal is close to a bus stop     

城市轨道交通噪声及其控制研究

近年来,随着经济的发展,修建城市轨道交通已成为解决大城市交通问题的首要选择,但同时也给沿线的居民和建筑物带来了噪声的环境污染。在分析城市轨道交通的噪声产生机理和传播规律的基础上,提出相应的控制措施和途径,为解决城市轨道交通发展中的噪声环境问题提供参考。     

城市交通系统管理与优化研究综述

根据城市路网交通需求与供给平衡关系,对城市交通问题产生的机理进行分析。通过对比分析国内外城市交通需求管理、交通运行管理及交通应急管理研究现状,指出多技术协同集成研究、交通参与者行为研究、交通政策评估与仿真研究、交通大数据应用研究,将成为未来研究的重要趋势。     

Intelligent infrastructure-based queue-end warning system for avoiding rear impacts

Accident avoidance is a very important part of enhancing road safety. The development of a queue-end warning system for highway work zones which automatically predicts queue-end location and alerts drivers so that rear-end collisions can be avoided has been described. In the absence of the widespread use of in-vehicle collision warning devices, dynamic messages about queue-end, displayed on portable variable message sign (PVMS) boards, are necessary for improving road safety. Although queues at selected locations along the road can be detected by the simple use of sensors, the changing nature of queue length would require numerous sensors to find the end of traffic queue. The reported queue-end warning system is based on a combination of sensors for detecting traffic and an artificial neural network (ANN) model-based algorithm for predicting queue-end location and issuing warning messages displayed on PVMS. Following the characterisation of work zones in terms of functional areas and geometrics, a microsimulator was calibrated and validated. Simulations were carried out next with traffic sensors and queue counter looped-in and the resulting data were used for training and validation of ANN models for queue length prediction. An automated information system was synthesised that integrates traffic sensors, ANN models, PVMS and potential links with other media. Selected results of ANN models illustrate their application in the queue-end warning system     

轻型轨道交通的设计与研究

解决市区交通阻塞与拥挤,发展轻轨交通,减少有害气体的排放,改善城市环境。     

元胞自动机：一种探索管理系统复杂性的有效工具

元胞自动机能利用简单的局部规则和离散方法描述复杂的全局的连续系统,已成为探索复杂系统的 一种有效工具。文章阐述了元胞自动机的发展历程、结构、特征及基本理论与方珐;介绍了元胞自动机在寡头 垄断行为、交通管理及工程运输、城市发展、市场营销、股票投资、企业战略等管理领域中的应用;指出元胞 自动机理论的优势与不足,并提出进一步的研究展望。     

Intelligent transport systems and effects on road traffic accidents: state of the art

The results from several reviews have been presented and the aspects of road safety associated with intelligent transport systems (ITS) applications have been addressed. The attempt is to make a state-of-the-art regarding effects on accidents by categorising systems according to levels of evaluations methods that have been applied. These categories are effects on behaviour, effects on accidents by proxy/surrogate methods, accident studies from real traffic, effects on accident types and finally by meta-analysis where weighted estimates of effects on accidents can be calculated. Thirty-three IT systems including driver assistance systems/advanced driver assistance systems, in-vehicle information systems, in-vehicle data-collection systems and road telematics have been listed. Effects based on meta-analysis are estimated for 11 systems, and single accident studies are found for an additional 2 systems. For the remaining 20 systems, no studies from real road traffic have been identified. Effects on accidents of antilocking brake systems and electronic stability control (ESC) are presented in more detail according to their effects on certain accident types. ESC appears to be very efficient in reducing the number of accidents. Behavioural adaptations to ITS are considered and discussed, especially in terms of compensation mechanisms. Four hypotheses regarding prediction of effects on accidents are stated according to whether systems increase or decrease 'windows of opportunities' by calling upon a driver behaviour model where emotions play a central role     

Optimizing 3PL service delivery using a cost-to-serve and action research framework

Full spectrum visibility and real-time management of increasingly complex, high-velocity operations will be the landmark practices of supply chain management in the twenty-first century. Integrating various business processes across functions is at the heart of supply chain management. As we survey the landscape, we can identify two sets of converging forces and newly emerging capabilities that will shape the way supply chains will develop in the near future. The first issue deals with the rapid rise of global third party logistics (3PL) companies that manage entire supply chains. The second issue has to do with how supply chain organizations plan and budget for a process of change, while simultaneously maintaining focus on full supply chain costs using a method known as the cost-to-serve (CSM) method. It is precisely these two issues that we address in this paper. Our first objective is to document the research conducted by the authors in the offshore oil and gas exploration and production industry. Our second objective is to use the CSM method to identify relevant cost drivers of 3PL services by nesting within an action research approach that pinpoints relevant operational constraints. The third objective is to use the action research framework and CSM to model various cost elements that could be incorporated into the objective function of a mathematical programming model. We compared the current design to the optimal design that we obtained from the model, and performed cost-benefit analysis to show the superiority of our procedure.     

Sustainable urban transportation development in China: A behavioral perspective

The rapid development of economics requires highly efficient and environment-friendly urban transportation systems. Such requirement presents challenges in sustainable urban transportation. The analysis and understanding of transportation-related behaviors provide one approach to dealing with complicated transportation activities. In this study, the management of traffic systems is divided into four levels with a structural and systematic perspective. Then, several special cases from the perspective of behavior, including purchasing behaviors toward new energy vehicles, choice behaviors toward green travel, and behavioral reactions toward transportation demand management policies, are investigated. Several management suggestions are proposed for transportation authorities to improve sustainable traffic management.     

The Construction of a Green Transportation System of China

Since the 21st century, the transportation industry in China has achieved rapid growth with a significant increase in the transport capacity; however the development has also greatly impacted the energy saving & environmental conservation. This paper takes into account non-commercial vehicles such as private cars in the statistics of energy consumption and pollution of Chinese transportation system. This method extends on previous methods which solely include commercial vehicles in these statistics. Based on more comprehensive quantitative data, it reviews the progress in the energy saving and environmental conservation efforts by the Chinese transportation industry and points out that the rapid increase of energy consumption and pollution emission and the deterioration of traffic congestion are prominent problems in the development of the Chinese transport industry. The main reasons for theses problems include the unbalanced development of different transport modes, the irrational layout of integrated transport hubs, the inadequate law, regulations and standards, and the use of suboptimal technology. Based on these findings, this paper proposes several goals for the construction of a green transportation system in China including the establishment of a transportation management system, the improvement of transportation energy efficiency, the control of environmental pollution and the alleviating of urban traffic congestion. Additionally, it points out that in order to build a green transportation system in China, multiple aspects should be enhanced, i.e., the formulation of traffic planning, the optimization of transport structure, the development of urban public transport, improvement of integrated hubs, administration of energy saving and environmental conservation, development of intelligent transportation systems, technical innovations, etc..     

The contribution of on-road studies of road user behaviour to improving road safety

For over 40 years transport safety researchers have been using methods of vehicle instrumentation to gain greater insights into the factors that contribute to road user crash risk and the associated crash factors. In the previous decade in particular the widespread availability of lower cost and more advanced methods of vehicle instrumentation and recording technologies are supporting the increasing number of on-road research studies worldwide. The design of these studies ranges from multi-method studies using instrumented test vehicles and defined driving routes, to field operational tests, through to much larger and more naturalistic studies. It is timely to assess the utility of these methods for studying the influences of driver characteristics and states, the design and operation of the road system, and the influences of in-vehicle technologies on behaviour and safety for various road user groups. This special issue considers the extent to which on-road studies using vehicle instrumentation have been used to advance knowledge across these areas of road safety research. The papers included in this issue illustrate how research using instrumented test vehicles continues to generate new knowledge, and how the larger scale United States and European naturalistic and field operational test studies are providing a wealth of data about road user behaviour in real traffic. This is balanced with a number of studies that present methodological developments in data collection and analysis methods that, while promising, need further validation. The use of on-road methods to accurately describe the behaviours occurring in everyday real-world conditions, to quantify risks for safety critical events, and an improved understanding of the factors that contribute to risk, clearly has huge potential to promote further road trauma reductions.     

Green Innovation for Urban Traffic

With the development of economy, the issue of urban traffic is becoming highlighted, the pollution of the urban traffic has become one of the main factors to influence environment. It faces the broader problem of achieving sustainable development of urban transportation at present. The current situation of urban traffic is analyzed through studying the existing articles at home and abroad in this paper; the problems such as green innovation of urban traffic are elaborated. In addition, this paper puts forward the relevant measures to promote the development of green innovation of the urban traffic.     

Multimodal user interface for traffic incident management in control room

Efficient road traffic incident management (TIM) in metropolitan areas is crucial for the smooth traffic flow and the mobility and safety of community. TIM requires fast and accurate collection and retrieval of critical data, such as incident conditions and contact information for the intervention crew, public safety organisations and other resources. Access to critical data by traffic control operators can be facilitated through various human-computer interfaces. The judicious introduction of a multimodal interaction paradigm to the user interfaces (UIs) for incident handling in a metropolitan transport management centre is discussed. Two research prototypes supporting speech and gestural interactions have been developed on the basis of the User Centred Design methodology, and their evaluations have been conducted through user studies. The user studies on the prototypes suggest that multimodal UIs (MMUIs) can provide traffic control operators with intuitive, cognitively efficient ways to record traffic incident conditions, facilitate fast retrieval of contact details, and support time-critical incident handling. The research prototypes described herein represent some initial steps for the longer-term deployment of advanced MMUI systems for emergency management     

Context of use as a factor in determining the usability of in-vehicle devices

In recent years, the issue of usability of in-vehicle devices has received growing attention. This is in line with the increase in functionality of these devices, which has been accompanied by the introduction of various new interfaces to facilitate the user–device interaction. The complexity and diversity of the driving task presents a unique challenge in defining usability: user interaction with in-vehicle devices creates a ‘dual task’ scenario, in which conflicts can arise between primary and secondary driving tasks. This, and the safety-critical nature of driving, must be accounted for in defining and evaluating the usability of in-vehicle devices. It is evident that defining usability depends on the context of use of the device in question. The aim of this review therefore is to define usability for in-vehicle devices by selecting a set of criteria to describe the various factors which contribute to usability in this specific context of use.     

A computerized approach to the New York Cityschool bus routing problem

Transportation is an area where operations research has had a great impact on systems by improving service quality and reducing operating costs. In particular, one of the most visible applications is in routing and scheduling school buses. In this paper we investigate various issues related to the development of a computerized system to help route and schedule school buses throughout the five boroughs of New York City. The routing problem presents many challenges because of its magnitude, the vast resources involved and the intricacies one encounters when routing in a completely urban environment. We analyze various aspects of the problem including the generation of routes in the Borough of Manhattan and provide a solution requiring far fewer buses than are currently in use. The computerized system, called CATS, incorporating many of the results obtained in this research, is currently being used to route Special Education students.     

Estimation of the Impact of Traveler Information Apps on Urban Air Quality Improvement

With the rapid growth of vehicle population and vehicle miles traveled, automobile emission has become a severe issue in the metropolitan cities of China. There are policies that concentrate on the management of emission sources. However, improving the operation of the transportation system through apps on mobile devices, especially navigation apps, may have a unique role in promoting urban air quality. Real-time traveler information can not only help travelers avoid traffic congestion, but also advise them to adjust their departure time, mode, or route, or even to cancel trips. Will such changes in personal travel patterns have a significant impact in decreasing emissions? If so, to what extent will they impact urban air quality? The aim of this study is to determine how urban traffic emission is affected by the use of navigation apps. With this work, we attempt to answer the question of whether the real-time traffic information provided by navigation apps can help to improve urban air quality. Some of these findings may provide references for the formulation of urban traffic and environmental policies.     

城市噪声地图系统研究及试验性应用

对城市噪声地图系统建立进行框架性研究,并在此基础上开展试验性应用。提出在城市中建立噪声地图系统的必要性和其功能性,重点分析了系统的组成和建立步骤、关键技术和应用前景。对噪声地图系统在城市噪声的管理、噪声控制措施的优化和促进声环境质量的预警预报方面具有积极的探索意义。