[PDF] The Benefits Of Integrated Freeway Corridor Control During Non Recurring Congestion eBook

Author : Conrad L. Dudek
Publisher : Transportation Research Board
Page : 80 pages
File Size : 18,23 MB
Release : 1992
Category : Technology & Engineering
ISBN : 9780309053044

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This synthesis will be of interest to state and local traffic engineers, transportation planners, transit operators, law enforcement officials, public information agencies, and others responsible for the transportation elements of freeway corridors. Information is provided on the policies and procedures for freeway corridor management, and descriptions of a number of techniques and practices are presented. Traffic growth and increasing congestion on urban freeways require a comprehensive approach toward managing the complex elements of freeway operations. This report of the Transportation Research Board provides information on freeway corridor management strategies, the components of management, examples of effective applications of the strategies, and benefits of freeway corridor management. The management techniques that are discussed include freeway surveillance and control; corridor street surveillance and control; high-occupancy vehicle facilities and incentives; police enforcement and traffic control; hazardous material and other truck traffic restrictions; alternative route planning; motorist assistance patrols; motorist information techniques; and traffic management for recurrent congestion, for incidents, for special events, and for work zones.

Author : Hani S. Mahmassani
Publisher :
Page : 4 pages
File Size : 12,74 MB
Release : 1998
Category : DYNASMART (Computer file)
ISBN :

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This study focuses on traffic congestion, primarily that occurring on freeway corridors in metropolitan areas. Lack of coordination in the operation of various components of the system is often a major source of inefficiency, resulting in greater delays to motorists than what might be achievable with the existing physical infrastructure. The main objective of the study is to improve corridor network management by coordinating the various control elements in a freeway corridor, for both recurrent and nonrecurrent congestion situations.

Author : David Schrank
Publisher : DIANE Publishing
Page : 24 pages
File Size : 22,1 MB
Release : 2008-10
Category : Transportation
ISBN : 1437905609

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Congestion continues to grow in America¿s urban areas. This report presents details on the 2004 trends, findings and what can be done to address the growing transportation problems. Trend data from 1982 to 2002 for 85 urban areas provides both a local view and a national perspective on the growth and extent of traffic congestion. The 2004 Report provides clear evidence that the time for improvements has arrived. Communicating the congestion levels and the need for improvements is a goal of this report. The decisions about which, and how much, improvement to fund will be made at the local level according to a variety of goals, but there are some broad conclusions that can be drawn from this database. Tables.

Author : Xu Wang
Publisher :
Page : 229 pages
File Size : 46,55 MB
Release : 2015
Category : Ramp metering (Traffic engineering)
ISBN :

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Active bottlenecks limit traffic flow on freeway corridors. To relieve bottleneck severity, ramp metering (RM), variable speed limit (VSL) and their integration are often implemented to control the on-ramp and mainline input flow. Currently, freeway operation has become proactive based on short-term prediction. Macroscopic traffic flow models are often applied as prediction models in proactive traffic control strategies. Prior to field implementation, the models need to be calibrated and validated carefully to ensure that they represent real-life traffic situations. This study proposes modifications for METANET model to adapt it to the unpredictability of bottleneck activation during peak hours. The modified model is calibrated and verified its improvement of model prediction accuracy from segment-specific parameters. The modified model is validated that it can replicate traffic state evolutions during peak hours and be applicable in proactive traffic control practice. Weaving maneuvers (i.e., intensive lane changes) are a major cause of bottlenecks during high-demand periods. To consider weaving impacts in RM, this study introduces a proactive optimal RM algorithm that uses dynamic weaving capacity at weaving segments. Sensitivities of capacity and capacity drop are applied to dynamically estimate weaving capacity within a macroscopic traffic flow model. The proposed traffic flow model conducts estimation in a model predictive control (MPC) frame-work. The proposed RM algorithm is evaluated in macro-simulation and its effectiveness is enhanced by real-time estimated weaving capacity. The RM control research reveals a need of theoretical methods for weaving capacity estimation. This study then defines a linear optimization problem to solve weaving capacity and then establishes a lane-changing model to constrain the weaving flows. The proposed method is evaluated and analyzed for sensitivity with field data from two weaving segments. The capacity estimates from the proposed model are consistent with those from the HCM 2010 model and with field observations. Moreover, the weaving capacity is sensitive to weaving maneuvers. The proposed method is finally applied to estimate the real-time maximum discharge flow rate; the estimates match field measurements. Next, this study presents a proactive integrated control of RM and VSL, with goals to improve network-wide travel time and traffic flow. By decoupling the traffic prediction and simulation models, the possible control error sources are analyzed. The evaluation reveals the proactive integrated control achieves an amelioration in total time spent (TTS) up to 13.65% and an increase in total travel distance (TTD) up to 3.41%. The isolated and integrated controls benefit the traffic network in different extent under different demand scenarios. In addition, control rate profiles are analyzed in detail and found that RM is activated during slight congestion and the most congested situation to assist VSL. Through the integration, the infrastructure utility is maximized. Speed transition zones are complex when dynamically created and shifted by VSL. This study then attempts to represent speed limit effect and estimate real-time driver compliance at speed transition zones. The field data from two speed transition zones are investigated for temporal and spatial variations of speed and driver compliance using statistical tests. After selecting several key factors from statistical tests, a linear regression is established to rank the contributions of the selected factors and other general factors proposed by previous research. The regression results confirm speed limit value, surrounding traffic speed and existence of activated speed enforcement or education devices contribute more to driver compliance. Finally, this study reports the preliminary VSL test and details its implementation procedure on Whitemud Drive, Edmonton, Canada. DynaTAM-VSL software is designed to realize all necessary functions for VSL filed implementation. The preliminary test is conducted, and the VSL control performance and reliability are evaluated. The results for before-and-after VSL control are finally analyzed in depth. The analysis compares average traffic speed, standard deviation of speed, total travel time and total travel distance. The results from this study confirm that VSL can relieve recurrent traffic congestion.

Author : Donald G. Capelle
Publisher : Transportation Research Board National Research
Page : 72 pages
File Size : 50,88 MB
Release : 1979
Category : Transportation
ISBN :

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This publication results from growing concern about increasing congestion on urban freeways. It provides an overview of proven traffic control techniques for reducing congestion and improving operations that will be of interest to highway administrators, legislators, and other public officials concerned with the management and operation of freeway systems. This synthesis of past and present practices describes operational and safety problems typical to an urban freeway corridor, a range of options for dealing with these problems, and guidelines for implementing and operating freeway control systems. The report is based on previous research, actual experience from operating freeway control systems in various parts of the United States, and numerous interviews with individuals having responsibility for those systems. General guidance is provided for the planning and implementation of freeway control projects at the executive and administrative levels.

Author : Imad L. Al-Qadi
Publisher : CRC Press
Page : 924 pages
File Size : 28,47 MB
Release : 2008-11-01
Category : Technology & Engineering
ISBN : 0203881206

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Internationally, significant attention is given to transport sustainability including planning, design, construction, evaluation, safety and durability of the road system. The 4th International Gulf Conference on Roads: Efficient Transportation and Pavement Systems - Characterization, Mechanisms, Simulation, and Modeling, hosted by the University o