8,092 research outputs found

    Using Operations Data for Planning the the Delaware Valley: First Steps

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    Real-time traffic operations data has been gathered for several years on an increasing number of roads throughout the Delaware Valley. The archives of this data are a tremendous potential resource for transportation planning. Use of the data, however, has posed significant technical challenges. This report summarizes how the data can be used, the state of operations data for planning in the Delaware Valley, and the results of two case studies. The first case study used data from the Pennsylvania Department of Transportation's Dynac system about speed and travel time on a section of I-76. The second case study used data provided by the I-95 Corridor Coalition Vehicle Probe Project (VPP) from INRIX, a private-sector traffic data company. The second case study analyzed duration of congestion on weekdays in 2009 for freeways in the Delaware Valley. This analysis was used in the region's 2011 Congestion Management Process

    Measuring the Quality of Arterial Traffic Signal Timing – A Trajectory-based Methodology

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    Evaluating the benefits from traffic signal timing is of increasing interest to transportation policymakers, operators, and the public as integrating performance measurements with agencies’ daily signal timing management has become a top priority. This dissertation presents a trajectory-based methodology for evaluating the quality of arterial signal timing, a critical part of signal operations that promises reduced travel time and fewer vehicle stops along arterials as well as improved travelers’ perception of transportation services. The proposed methodology could significantly contribute to performance-oriented signal timing practices by addressing challenges regarding which performance measures should be selected, how performance measurements can be performed cost-effectively, and how to make performance measures accessible to people with limited knowledge of traffic engineering. A review of the current state of practice and research was conducted first, indicating an urgent research need for developing an arterial-level methodology for signal timing performance assessments as the established techniques are mostly based on by-link or by-movement metrics. The literature review also revealed deficiencies of existing performance measures pertaining to traffic signal timing. Accordingly, travel-run speed and stop characteristics, which can be extracted from vehicle GPS trajectories, were selected to measure the quality of arterial signal timing in this research.Two performance measures were then defined based on speed and stop characteristics: the attainability of ideal progression (AIP) and the attainability of user satisfaction (AUS). In order to determine AIP and AUS, a series of investigations and surveys were conducted to characterize the effects of non-signal-timing-related factors (e.g., arterial congestion level) on average travel speed as well as how stops may affect travelers’ perceived quality of signal timing. AIP was calculated considering the effects of non-signal-timing-related factors, and AUS accounted for the changes in the perceived quality of signal timing due to various stop circumstances.Based upon AIP and AUS, a grade-based performance measurement methodology was developed. The methodology included AIP scoring, AUS scoring, and two scoring adjustments. The two types of scoring adjustments further improved the performance measurement results considering factors such as cross-street delay, pedestrian delays, and arterial geometry. Furthermore, the research outlined the process for implementing the proposed methodology, including the necessary data collection and the preliminary examination of the applicable conditions. Case studies based on real-world signal re-timing projects were presented to demonstrate the effectiveness of the proposed methodology in enhancing agencies’ capabilities of cost-effectively monitoring the quality of arterial signal timing, actively addressing signal timing issues, and reporting the progress and outcomes in a concise and intuitive manner

    Using Performance Measures to Improve Signal System Performance

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    Recent emphasis on improving signal system performance has prompted research on the collection of enhanced quantitative data for making operational decisions, the development of a systematic method for monitoring and recording system performance and the definition of quantitative performance measures to identify opportunities to improve corridor traffic operations. This document summarizes the highlights from several publications which document the motivation, theory and application of traffic signal performance measures. Topics discussed include the advantages of monitoring signal system performance without labor intensive field observations. The benefits of real time monitoring and evaluation of signal system performance as well as system troubleshooting. The performance measures identified are capable of revealing the accuracy of equipment installation, green time allocation to adequately serve vehicle demand and quality of arterial progression. They allow agencies the opportunity to more efficiently manage their infrastructure which in turn provides benefits to the local agencies, the traveling public and the overall signal system performance. The document closes by discussing the equipment requirements, provides an overview of the performance measures and has a brief discussion of funding used for signal system infrastructure improvement

    Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 145

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    This bibliography lists 301 reports, articles, and other documents introduced into the NASA scientific and technical information system in August 1975

    Regional Data Archiving and Management for Northeast Illinois

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    This project studies the feasibility and implementation options for establishing a regional data archiving system to help monitor and manage traffic operations and planning for the northeastern Illinois region. It aims to provide a clear guidance to the regional transportation agencies, from both technical and business perspectives, about building such a comprehensive transportation information system. Several implementation alternatives are identified and analyzed. This research is carried out in three phases. In the first phase, existing documents related to ITS deployments in the broader Chicago area are summarized, and a thorough review is conducted of similar systems across the country. Various stakeholders are interviewed to collect information on all data elements that they store, including the format, system, and granularity. Their perception of a data archive system, such as potential benefits and costs, is also surveyed. In the second phase, a conceptual design of the database is developed. This conceptual design includes system architecture, functional modules, user interfaces, and examples of usage. In the last phase, the possible business models for the archive system to sustain itself are reviewed. We estimate initial capital and recurring operational/maintenance costs for the system based on realistic information on the hardware, software, labor, and resource requirements. We also identify possible revenue opportunities. A few implementation options for the archive system are summarized in this report; namely: 1. System hosted by a partnering agency 2. System contracted to a university 3. System contracted to a national laboratory 4. System outsourced to a service provider The costs, advantages and disadvantages for each of these recommended options are also provided.ICT-R27-22published or submitted for publicationis peer reviewe

    Integrating spatial and temporal approaches for explaining bicycle crashes in high-risk areas in Antwerp (Belgium)

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    The majority of bicycle crash studies aim at determining risk factors and estimating crash risks by employing statistics. Accordingly, the goal of this paper is to evaluate bicycle-motor vehicle crashes by using spatial and temporal approaches to statistical data. The spatial approach (a weighted kernel density estimation approach) preliminarily estimates crash risks at the macro level, thereby avoiding the expensive work of collecting traffic counts; meanwhile, the temporal approach (negative binomial regression approach) focuses on crash data that occurred on urban arterials and includes traffic exposure at the micro level. The crash risk and risk factors of arterial roads associated with bicycle facilities and road environments were assessed using a database built from field surveys and five government agencies. This study analysed 4120 geocoded bicycle crashes in the city of Antwerp (CA, Belgium). The data sets covered five years (2014 to 2018), including all bicycle-motorized vehicle (BMV) crashes from police reports. Urban arterials were highlighted as high-risk areas through the spatial approach. This was as expected given that, due to heavy traffic and limited road space, bicycle facilities on arterial roads face many design problems. Through spatial and temporal approaches, the environmental characteristics of bicycle crashes on arterial roads were analysed at the micro level. Finally, this paper provides an insight that can be used by both the geography and transport fields to improve cycling safety on urban arterial roads
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