77,915 research outputs found

    A Model of the Rise and Fall of Roads

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    Transportation network planning decisions made at one point of time can have profound impacts in the future. However, transportation networks are usually assumed tobe static in models of land use. A better understanding of the natural growth pattern of roads will provide valuable guidance to planners who try to shape the future network. This paper analyzes the relationships between network supply and travel demand, and describes a road development and degeneration mechanism microscopically at the linklevel. A simulation model of transportation network dynamics is developed, involving iterative evolution of travel demand patterns, network revenue policies, cost estimation,and investment rules. The model is applied to a real-world congesting network – the Twin Cities transportation network which comprises nearly 8,000 nodes and more than 20,000 links, using network data collected since year 1978. Four experiments are carried out with different initial conditions and constraints, the results from which allow us toexplore model properties such as computational feasibility, qualitative implications, potential calibration procedures, and predictive value. The hypothesis that roadhierarchies are emergent properties of transportation networks is confirmed, and the underlying reasons discovered. Spatial distribution of capacity, traffic flow, andcongestion in the transportation network is tracked over time. Potential improvements to the model in particular and future research directions in transportation network dynamicsin general are also discussed.Transportation network dynamics, Urban planning, Road suppl

    A preliminary safety evaluation of route guidance comparing different MMI concepts

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    Estimation of indirect cost and evaluation of protective measures for infrastructure vulnerability: A case study on the transalpine transport corridor

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    Infrastructure vulnerability is a topic of rising interest in the scientific literature for both the general increase of unexpected events and the strategic importance of certain links. Protective investments are extremely costly and risks are distributed in space and time which poses important decision problems to the public sector decision makers. In an economic prospective, the evaluation of infrastructure vulnerability is oriented on the estimation of direct and indirect costs of hazards. Although the estimation of direct costs is straightforward, the evaluation of indirect cost involves factors non-directly observable making the approximation a difficult issue. This paper provides an estimate of the indirect costs caused by a two weeks closure of the north-south Gotthard road corridor, one of the most important infrastructure links in Europe, and implements a cost-benefit analysis tool that allows the evaluation of measures ensuring a full protection along the corridor. The identification of the indirect cost relies on the generalized cost estimation, which parameters come from two stated preference experiments, the first based on actual condition whereas the second assumes a road closure. The procedure outlined in this paper proposes a methodology aimed to identify and quantify the economic vulnerability associated with a road transport infrastructure and, to evaluate the economic and social efficiency of a vulnerability reduction by the consideration of protective measures.infrastructure vulnerability, choice experiment, cost-benefit analysis, freight transport

    Telematics programme (1991-1994). EUR 15402 EN

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    Road pricing from a geographical perspective: a literature review and implications for research into accessibility

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    Road pricing policies have been a subject of research for many decades. Even though until now examples of actual implication in the real world are limited, many different road-pricing measures have been considered, both in literature as well as in the political debate in several countries. However, most literature focuses on economic aspects, more or less ignoring spatial consequences. In this paper we will concentrate on the spatial effects of pricing policy and introduce the typical geographic concept of accessibility into the discussion about pricing policy. The paper firstly gives some backgrounds of pricing policies. Some objectives of road pricing in general are given. Furthermore some examples of already implemented pricing measures in countries all over the world are mentioned. General literature concerning pricing policies aims specifically on economic effects. This is mainly because of the typical economic aspects, which can be found in the theory of pricing policy such as the pricing of a scarce good as infrastructure capacity, related to time aspects. Also studies concerning acceptability of road pricing policies are discussed, because acceptance plays an important role in the implementation of pricing policies. The paper shortly addresses some of the economic and acceptability related literature. But the literature review of the paper focuses specifically on the geographical aspects of pricing policies. These geographical aspects have received much less attention so far although road-pricing measures may cause important spatial effects. Therefore the second part of the paper focuses on these geographical aspects. A specific research field in geography is accessibility. Accessibility is a concept that connects infrastructure and land-use. The research fields of accessibility and pricing policies in isolation are well elaborated. However, the link between road pricing policies and accessibility (measures) forms a new research field. The paper explains the importance of the concept of accessibility. In practice accessibility can be computed with accessibility measures. These measures form quantifications of accessibility. Different types of accessibility measures exist differing in concept as well as complexity. All these measures have in common that transport costs are not included at all or at least not in a realistic way. After explaining the concept of accessibility different categories of accessibility measures are explained and their general advantages and disadvantages are given. Furthermore possibilities to adapt or improve accessibility measures are discussed. After this discussion the actual link between road pricing policies and accessibility measures is explained. The discussion begins with the presentation of a conceptual model of the accessibility (and spatial) effects of road pricing. Subsequently an observation is made where current measures fall short to include pricing policy costs in a realistic way. This observation will lead to the determination of directions for improvement. Besides the general possibilities to adjust different accessibility measures, each measure is specifically evaluated on the ability to improve the way of describing accessibility effects of road pricing.

    Getting on Track: Good Investments for Pennsylvania's Public Transit System

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    Provides an overview of the state's transit system and summarizes opportunities for investment in rapid transit, rail, and bus lines in each region. Includes policy recommendations

    Machine learning for early detection of traffic congestion using public transport traffic data

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    The purpose of this project is to provide better knowledge of how the bus travel times is affected by congestion and other problems in the urban traffic environment. The main source of data for this study is second-level measurements coming from all buses in the Linköping region showing the location of each vehicle.The main goal of this thesis is to propose, implement, test and optimize a machine learning algorithm based on data collected from regional buses from Sweden so that it is able to perform predictions on the future state of the urban traffic.El objetivo principal de este proyecto es proponer, implementar, probar y optimizar un algoritmo de aprendizaje automático basado en datos recopilados de autobuses regionales de Suecia para que poder realizar predicciones sobre el estado futuro del tráfico urbano.L'objectiu principal d'aquest projecte és proposar, implementar, provar i optimitzar un algoritme de machine learning basat en dades recollides a partir d'autobusos regionals de Suècia de manera per poder realitzar prediccions sobre l'estat futur del trànsit urbà

    Durable, Cost-Effective Pavement Markings Phase I: Synthesis of Current Research, June 2001

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    Pavement marking technology is a continually evolving subject. There are numerous types of materials used in the field today, including (but not limited to) paint, epoxy, tape, and thermoplastic. Each material has its own set of unique characteristics related to durability, retro reflectivity, installation cost, and life-cycle cost. The Iowa Highway Research Board was interested in investigating the possibility of developing an ongoing program to evaluate the various products used in pavement marking. This potential program would maintain a database of performance and cost information to assist state and local agencies in determining which materials and placement methods are most appropriate for their use. The Center for Transportation Research and Education at Iowa State University has completed Phase I of this research: to identify the current practice and experiences from around the United States to recommend a further course of action for the State of Iowa. There has been a significant amount of research completed in the last several years. Research from Michigan, Pennsylvania, South Dakota, Ohio, and Alaska all had some common findings: white markings are more retro reflective than yellow markings; paint is by-and-large the least expensive material; paint tends to degrade faster than other materials; thermoplastic and tapes had higher retro reflective characteristics. Perhaps the most significant program going on in the area of pavement markings is the National Transportation Product Evaluation Program (NTPEP). This is an ongoing research program jointly conducted by the American Association of State Highway and Transportation Officials and its member states. Field and lab tests on numerous types of pavement marking materials are being conducted at sites representing four climatological areas. These results are published periodically for use by any jurisdiction interested in pavement marking materials performance.At this time, it is recommended that the State of Iowa not embark on a test deck evaluation program. Instead, close attention should be paid to the ongoing evaluations of the NTPEP program. Materials that fare well on the NTPEP test de cks should be considered for further field studies in Iowa
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