Download or read book Dilemma Zone Protection and Signal Coordination at Closely spaced High speed Intersections written by Prahlad D. Pant and published by . This book was released on 2001 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: A feasibility study of dilemma zone problems, performed by collecting and analyzing traffic flow data at a high-speed signalized intersection, showed that the maximum green extension or cutback needed to get a vehicle out of the dilemma zone is generally no more than 2 seconds. If we scan all vehicles on a link just a few seconds before the beginning of a yellow interval, we may be able to extend or cut back the green interval so that the vehicles can avoid the dilemma zone. For each vehicle approaching an intersection on the link that is about to turn yellow, there is a time interval such that (a) the vehicle will be in the dilemma zone without green extension (or cutback) or (b) it will be in the dilemma zone when there are T seconds of extension (or cutback). So the task is to find the smallest nonnegative integer T that is not in any of these time intervals and extend (or cut back) the current interval by T seconds. This T can always be found and assuming there are no other restrictions, dilemma zones can be avoided and the extension (or cutback) is done at most once for each green interval. The simulation study, performed by modifying the source codes of NETSIM, showed that the signal timing generated by a bandwidth maximization program (PASSER-II) resulted in a lower number of vehicles in the dilemma zone than that generated by a delay minimization program (TRANSYT-7F). Additionally, the signal timing generated by the combination of the two programs, that is, by minimizing delay within the constraint of bandwidth maximization, resulted in an even lower number of vehicles in the dilemma zone than those generated by each program alone. The technique developed in this study can be implemented if the speeds and positions of all vehicles on the roadway can be recorded at small time intervals (e.g., 1 sec). Recommendations are made for implementing and testing the developed technique.
Download or read book Dilemma Zone Protection and Signal Coordination at Closely spaced High speed Intersections written by Prahlad D. Pant and published by . This book was released on 2006 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt: A feasibility study of dilemma zone problems, performed by collecting and analyzing traffic flow data at a high-speed signalized intersection, showed that the maximum green extension or cutback needed to get a vehicle out of the dilemma zone is generally no more than two seconds. Scanning all vehicles on a link just seconds before the beginning of a yellow interval may extend or cut back the green interval so that vehicles can avoid the dilemma zone. For each vehicle approaching an intersection on a link about to turn yellow there is a time interval that (a) the vehicle will be in dilemma zone without green extension (or cutback) or (b) it will be in dilemma zone when there is T seconds of extension (or cutback). The task becomes to find the smallest nonnegative integer T that is not in any of these time intervals and extend or cutback the current interval by T seconds. This T can always be found and assuming there are no other restrictions, dilemma zones can be avoided and the extension or cutback is done at most once for each green interval. The simulation study, performed by modifying the source codes of NETSIM, showed that the signal timing generated by a bandwidth maximization program (PASSER II) resulted in a lower number of vehicles in dilemma zone than that generated by a delay minimization program (TRANSYT-7F). Additionally, the signal timing generated by the combination of the two programs, that is, by minimizing delay within the constraint of bandwidth maximization, resulted in even lower number of vehicles in dilemma zone than those generated by each program alone. The technique developed in this study can be implemented if the speeds and positions of all vehicles in the roadway can be recorded at small time intervals (e.g., 1 sec.). Recommendations are made for implementing and testing the developed technique.
Download or read book Field Testing and Implementation of Dilemma Zone Protection and Signal Coordination at Closely spaced High speed Intersections written by and published by . This book was released on 2005 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: Historically, high speed signalized intersections have reported many crashes and have always posed a challenge to traffic engineers for enhancing safety at these intersections. The area close to the intersection, called the dilemma zone, poses a high accident potential for the driver in stopping safely during the yellow interval or in proceeding through the intersection before the beginning of red. The driver is in a potentially hazardous situation whereby, if he tries to cross the intersection at the onset of red interval, he may end up in an angle accident with the cross street traffic or if he accelerates through yellow, he may end up in a rear-end collision. The uncertain situation in a dilemma zone can potentially lead to rear-end or right angle collisions.
Download or read book Dilemma Zone Protection on High speed Arterials written by Bhaven Naik and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Driver behavior within the dilemma zone can be a major safety concern at high-speed signalized intersections, especially for heavy trucks. The Nebraska Department of ROADS (NDOR) has developed an implemented an Actuated Advance Warning (AAW) dilemma zone protection system. The AAW system has been documented as being effective at improving traffic safety at isolated signalized intersections. However, the system is yet to be used at signalized intersections operating in the coordinated mode. This study tested the feasibility of deploying the system on arterials where the signals are closely spaced and operate in a coordinated mode. A microsimulation approach -- integration of traffic microsimulation and surrogate safety performance measures -- was developed to assess the potential benefits (safety and operation) in-lieu of observed traffic and crash data. The analysis of conflicts indicated that, on average, there were 30%, 7%, and 30% reductions in the number of rear-end, lane change, and crossing conflicts respectively when the AAW system was used. In terms of the relative productivity of the system, the number of vehicles that were processed during a specified analysis period revealed that there were generally more vehicles processed when the AAW system was not in place. Also, the overall link travel times were slightly higher when the system was in place" (page viii).
Download or read book Human Factors Guidelines for Road Systems written by John L. Campbell and published by Transportation Research Board. This book was released on 2008 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: NCHRP report 600 explores human factors principles and findings for consideration by highway designers and traffic engineers. The report is designed to help the nonexpert in human factors to consider more effectively the roadway user's capabilities and limitations in the design and operation of highway facilities.
Download or read book Progress in Location Based Services 2014 written by Georg Gartner and published by Springer. This book was released on 2014-11-05 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a general picture of recent research activities related to location-based services. Such activities emerged in the last years especially concerning issues of outdoor/indoor positioning, smart environment, spatial modelling, personalization and context-awareness, cartographic communication, novel user interfaces, crowdsourcing, social media, big data analysis, usability and privacy. This book is comprised of a selection of the best papers presented during the 11th International Symposium on Location Based Services, which was held in Vienna (Austria) between 26th and 28th November 2014.
Download or read book Placement of Detection Loops on High Speed Approaches to Traffic Signals written by and published by . This book was released on 2010 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report contains the results of the NC Department of Transportation research project Placement of Detection Loops on High Speed Approaches to Traffic Signals (HWY 2007-13). The goal of this project was to determine the best places to locate detectors on the approaches to high-speed signalized intersections and the best signal control strategy to employ in conjunction with those sensor placement ideas to minimize dilemma zone occurrences.
Download or read book Signalized Intersections written by Daiheng Ni and published by Springer Nature. This book was released on 2020-02-27 with total page 335 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook introduces the basics principles of intersection signalization including need studies, signal phasing, sequencing, timing, as well as more advanced topics such as detectors, controllers, actuated control schemes, and signal coordination. The book covers a variety of topics critical to the set up and operation of intersections controlled by traffic signals. Professor Ni imparts a basic understanding of how intersections work, what justifies intersection signalization, how to properly design phasing and timing plans for intersections, what is needed to run traffic-responsive signals, the workings of traffic controller cabinets, and how to set up signal coordination at multiple intersections—competencies essential to transportation professionals in charge of traffic operation at federal, state, and local levels. Aimed at students in transportation engineering programs with a focus on intersection signalization, the book is also ideal for researchers of traffic dynamics and municipal civil and transportation engineers.
Download or read book A Novel Approach to Dilemma Zone Problem for High Speed Signalized Intersections written by Venkata Suresh Raavi and published by . This book was released on 2010 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Safety and efficiency are both major concern at high-speed intersections. It has been a major challenge for traffic engineers over the years to increase efficiency without sacrificing delay. An IntelliDrive signal control system was developed in the University of Akron's transportation lab based on the concept of IntelliDrive technology that can improve safety significantly while retaining efficiency. The new intelligent signal control system can address the dynamic dilemma zone problem, thus providing maximum safety at intersections. Every vehicle in the system is addressed to its own dilemma boundary rather than addressing dilemma zone for the whole intersection approach. By obtaining advance speed information, vehicle classification, vehicle location from the stop line, for every vehicle for every second in the system in real time, unneeded extensions can be avoided. Thus the intersection not only operates more safely, but also more efficiently because of the proposed algorithm logic that utilizes IntelliDrive technology. IntelliDrive test bed was created in VISSIM simulation platform and tested for operational efficiency when safety criteria are met. This thesis also discusses the characteristics of the Peak Flow Factor (PFF) which is the ratio between peak hourly volume and peak flow rate within the hour. Despite the fact that the Highway Capacity Manual (HCM) requires use of this ratio in evaluating the Levels of Service (LOS) of roadway facilities, a very limited amount of prior research has been made on its variability. Subsequently, the HCM established a time interval of 15 minutes for obtaining the peak flow rate without much explanation on why this time interval was chosen. In order to investigate the PFF's effectiveness for representing the variation of flow within peak hour, this research focuses on PFF analysis and time series models of the PFF at various time intervals for signalized isolated intersections. Results showed that the PFF decreased when time interval decreased and that significant differences in the stability were apparent when each time interval were compared. In addition, the developed time series models showed the the[sic] PFF can be forecasted with relative accuracy and simulation models within this study demonstrated the test results from data are dependable."--Abstract.
Download or read book Report written by and published by . This book was released on 1964 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ohio Documents written by and published by . This book was released on 2002 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book State Planning and Research Program written by and published by . This book was released on 1999 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Traffic Signal Timing Manual written by U.s. Department of Transportation and published by CreateSpace. This book was released on 2015-02-20 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report serves as a comprehensive guide to traffic signal timing and documents the tasks completed in association with its development. The focus of this document is on traffic signal control principles, practices, and procedures. It describes the relationship between traffic signal timing and transportation policy and addresses maintenance and operations of traffic signals. It represents a synthesis of traffic signal timing concepts and their application and focuses on the use of detection, related timing parameters, and resulting effects to users at the intersection. It discusses advanced topics briefly to raise awareness related to their use and application. The purpose of the Signal Timing Manual is to provide direction and guidance to managers, supervisors, and practitioners based on sound practice to proactively and comprehensively improve signal timing. The outcome of properly training staff and proactively operating and maintaining traffic signals is signal timing that reduces congestion and fuel consumption ultimately improving our quality of life and the air we breathe. This manual provides an easy-to-use concise, practical and modular guide on signal timing. The elements of signal timing from policy and funding considerations to timing plan development, assessment, and maintenance are covered in the manual. The manual is the culmination of research into practices across North America and serves as a reference for a range of practitioners, from those involved in the day to day management, operation and maintenance of traffic signals to those that plan, design, operate and maintain these systems.
Download or read book Evaluation of Dilemma Zone Advance Warning Signals at High Speed Signalized Intersections written by Vikram Chakravarthy Kalyani and published by . This book was released on 2006 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Advance Warning Signals on High Speed Signalized Intersections written by Peter T. Martin and published by . This book was released on 2003 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of a Second Generation Detection control System for Safer Operation of High Speed Signalized Intersections written by Karl H. Zimmerman and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This Innovations Deserving Exploratory Analysis project improved and evaluated a detection-control system (D-CS) for enhanced traffic safety at high speed signalized intersections. A literature review was conducted to identify potential enhancements to the D-CS control algorithm required to create the "second generation" D-CS algorithm. The needed enhancements included dilemma zone protection based on vehicle size, real-time dilemma zone changes, coordination, and real-time measures of effectiveness reporting. After selecting the most feasible enhancements, the control algorithm was modified and tested in the laboratory. Based on laboratory test results and refinements, a "second generation" D-CS control algorithm was developed capable of providing dilemma zone protection specific to vehicle type using a modified system to prevent max out during "Stage 2" operation.
Download or read book Guidelines for Timing Yellow and All red Intervals at Signalized Intersections written by Hugh W. McGee and published by Transportation Research Board. This book was released on 2012 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB National Cooperative Highway Research Program (NCHRP) Report 731: Guidelines for Timing Yellow and All-Red Intervals at Signalized Intersections offers guidance for yellow change and all-red clearance intervals at signalized intersections. The guidelines provide a framework that can be easily applied by state and local transportation agencies.
