144 research outputs found

    Safe System Strategic Plan

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    DTFH6116D00055LThe Safe System Strategic Plan provides a roadmap for the advancement of the Safe System Approach in the U.S. It describes the Safe System Approach, discusses the process involved in building the plan, outlines how to advance a Safe System mindset, and describes steps necessary to implement Safe System practices within the transportation community in the U.S. This plan focuses on the role of road system owners and operators in applying the Safe System Approach to design, build, and operate safer roads. This plan aims to educate transportation professionals on the effectiveness of the Safe System Approach while also offering guidance on how to prioritize safety in the U.S. as a means to achieving zero traffic fatalities

    Towards a realistic microscopic description of highway traffic

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    Simple cellular automata models are able to reproduce the basic properties of highway traffic. The comparison with empirical data for microscopic quantities requires a more detailed description of the elementary dynamics. Based on existing cellular automata models we propose an improved discrete model incorporating anticipation effects, reduced acceleration capabilities and an enhanced interaction horizon for braking. The modified model is able to reproduce the three phases (free-flow, synchronized, and stop-and-go) observed in real traffic. Furthermore we find a good agreement with detailed empirical single-vehicle data in all phases.Comment: 7 pages, 7 figure

    Microsimulation models incorporating both demand and supply dynamics

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    There has been rapid growth in interest in real-time transport strategies over the last decade, ranging from automated highway systems and responsive traffic signal control to incident management and driver information systems. The complexity of these strategies, in terms of the spatial and temporal interactions within the transport system, has led to a parallel growth in the application of traffic microsimulation models for the evaluation and design of such measures, as a remedy to the limitations faced by conventional static, macroscopic approaches. However, while this naturally addresses the immediate impacts of the measure, a difficulty that remains is the question of how the secondary impacts, specifically the effect on route and departure time choice of subsequent trips, may be handled in a consistent manner within a microsimulation framework. The paper describes a modelling approach to road network traffic, in which the emphasis is on the integrated microsimulation of individual trip-makers’ decisions and individual vehicle movements across the network. To achieve this it represents directly individual drivers’ choices and experiences as they evolve from day-to-day, combined with a detailed within-day traffic simulation model of the space–time trajectories of individual vehicles according to car-following and lane-changing rules and intersection regulations. It therefore models both day-to-day and within-day variability in both demand and supply conditions, and so, we believe, is particularly suited for the realistic modelling of real-time strategies such as those listed above. The full model specification is given, along with details of its algorithmic implementation. A number of representative numerical applications are presented, including: sensitivity studies of the impact of day-to-day variability; an application to the evaluation of alternative signal control policies; and the evaluation of the introduction of bus-only lanes in a sub-network of Leeds. Our experience demonstrates that this modelling framework is computationally feasible as a method for providing a fully internally consistent, microscopic, dynamic assignment, incorporating both within- and between-day demand and supply dynamic

    Main flexible pavement and mix design methods in Europe and challenges for the development of an european method

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    Pavement and mix design represent one of the key components within the life cycle of a road infrastructure, with links to political, economic, technical, societal and environmental issues. Recent researches related to the characteristics of materials and associated behavior models both for materials and pavement, made it appropriate to consider updating current pavement design methods, and especially in the USA this has already been in process while in Europe uses of the methods developed in the early 1970s. Thus, this paper firstly presents a brief historical overview of pavement design methods, highlighting early limitations of old empirical methods. Afterwards, French, UK and Shell methods currently in use in Europe will be presented, underlining their main components in terms of methodology, traffic, climatic conditions and subgrade. The asphalt mix design and modeling in Europe are presented with their inclusion in the pavement design methods. Finally, the main challenges for the development of a European pavement design method are presented as well as the recent research developments that can be used for that methodThe second author would like to express the support of Portuguese National Funding Agency for Science, Research and Technology (FCT) through scholarship SFRH/BSAB/114415/ 2016. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.info:eu-repo/semantics/publishedVersio

    ACCIDENTS THAT SHOULD NOT HAPPEN

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    On October 25, 1995, seven high school students were killed in an accident when their Fox River Grove, Illinois, school bus was struck by a commuter train while stopped at a signalized highway-rail crossing. The circumstances that led to this tragic accident were investigated by the National Transportation Safety Board (NTSB). Also, a Blue Ribbon Working Group worked with a task force of the United States Department of Transportation to review the decision-making process for designing, constructing, and operating rail crossings. The principal finding of their report, Accidents That Shouldn\u27t Happen, was that better cooperation, communication, and education are necessary among responsible parties if accidents and fatalities are to be reduced at highway-rail grade crossings. An NTSB letter explaining the circumstances of the Fox River Grove bus accident is included

    FLASHING AMBER LIGHTS INCREASE CHILDREN\u27S SAFETY

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    A $150,000 investment in new amber-lights technology for Prince Edward Island, Canada, school buses is designed to increase the safety for all children and create new expectations for all drivers to pay special attention to flashing yellow lights. The flashing amber lights were installed in all buses over the summer of 1999. With the new system, the traditional red lights will continue to flash when the school bus stops to either pick up or drop off children. In addition, the new amber light will now flash for a period of time before the red lights flash, to alert drivers that the bus is preparing to stop. When the red lights begin to flash, traffic in either direction must stop

    FEDERAL REGISTER NOTICES

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    Between December 21, 1999, and January 4, 2000, the Federal Highway Administration and the Federal Transit Administration issued a number of requests for comments and final notices on federal regulations of interest to the transportation community. This feature offers a short description of each announcement, including the date that it was published. Regulation topics include traffic control devices on federal-aid and other streets and highways; traffic control for highway-rail grade crossings; best practices procurement manual; Transportation Equity Act for the 21st Century; and revisions of the Manual on Uniform Traffic Control Devices in the areas of regulatory signs, general markings and signals, temporary traffic control devices, and standards for center line and edge line markings

    UNITED KINGDOM TO REQUIRE BELLS ON ALL NEW BIKES

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    The United Kingdom (U.K.) Transport Ministry announced the intent to introduce legislation requiring all new adult bicycles to be fitted with a bell. The U.K. Highway Code already advises cyclists to ring their bell to make others aware of their presence, but many bikes do not have one. Fitting a bell to all new bikes gives riders the ability to alert other road users, especially pedestrians, of their presence

    URBAN TASK FORCE SETS OUT 100 WAYS TO REVIVE ENGLAND\u27S TOWNS AND CITIES

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    The challenge of household growth creates the opportunity to improve quality of life in England\u27s towns and cities--and at the same time protect the countryside--according to a major report from the government\u27s Urban Task Force. The report contains over 100 detailed recommendations, including committing at least 65% of transport public expenditure to walking, cycling, and public transport over the next 10 years and introducing Home Zones to give local people more control over traffic movement through their neighborhoods

    TRANSPORTATION OPERATIONS--THE NATIONAL DIALOGUE CONTINUES

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    In this feature, the National Steering Committee on Transportation Operations (NSCTO) provides an update on the National Dialogue on Transportation Operations (NDTO). During 1999 and early 2000, scores of transportation professionals participated in the NDTO through a series of small discussion groups and the NSCTO. In April 2000, this dialogue was expanded to include approximately 400 transportation professionals. A series of white papers was commissioned and published on the Web site for the Institute of Transportation Engineers. In addition, a Web survey of over 200 people was conducted. The NSCTO considered all input received and developed a set of objectives for an initiative. This article summarizes the immediate next steps, which will focus on some of the individual objectives, combinations of the objectives, or the total operations initiative depending on the users and audience. These include continuing and expanding the NDTO; using tools to more effectively manage and operate transportation management centers, corridors, incidents, work zones, traffic signal retiming, traveler information, emergency/disaster response, intermodal transfers, special events, Mayday systems, goods movement, roadway weather condition reporting, and transit systems; measuring performance of transportation systems; research, and funding
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