Download or read book Development Evaluation and Application of Left Turn Signal Warrants written by Jonathan Upchurch and published by . This book was released on 1991 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study dealt with five types of left turn signal phasing: permissive, leading exclusive, lagging exclusive, leading exclusive/permissive, and lagging exclusive/permissive. The objectives of this research project were to: (1) develop a research work plan to conduct a statistically valid study for the development of numerical warrants for left turn movements; and (2) prepare a database of available information on signalized intersections and select the intersections to be used in the future study. This report describes the database of Arizona signalized intersections created in this project, the findings on left turn accident rates for different types of left turn phasing (using a nonrandom sample), and results of a validation study of the TEXAS computer simulation model. It also presents a research work plan for a future research project.

Download or read book Evaluation of Safety and Development of Guidelines for Protected permitted Left turn Signal Controls written by Zongzhong Tian and published by . This book was released on 2009 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Estimated Highway Planning and Research Program written by and published by . This book was released on 1992 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of the Left Turn Red Arrow written by and published by . This book was released on 1982 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of Traffic Signal Displays for Protected permissive Left turn Control written by Christopher Lynn Brehmer and published by Transportation Research Board. This book was released on 2003 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Highway Research Abstracts written by and published by . This book was released on 1994 with total page 1006 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of Warrants for Installation of Dual Right turn Lanes at Signalized Intersections written by Yi Qi and published by . This book was released on 2012 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Right-turn lanes provide space for the deceleration and storage of right-turn vehicles, and separate turning vehicles from through movements. Dual right-turn lanes are increasingly used at urban intersections primarily for two reasons: (1) to accommodate high right-turn demands and avoid turn-pocket overflows, and/or (2) to prevent right-turn vehicles that exit from a nearby upstream freeway off-ramp (on the left of the roadway) from abruptly changing too many lanes toward the right-turn lane at the intersection. In addition, a number of other factors may affect the decisions on the installation of dual right-turn lanes. However, warrants for dual right lane installation are almost non-existent, leaving traffic engineers to rely on engineering judgment. This research aims to develop warrants for installation of dual right-turn lanes at signalized intersections. Both the operational and safety benefits/costs were analyzed by surveying traffic engineers and by conducting traffic simulation-based analysis. Microscopic traffic simulation model, VISSIM, was used to quantify the operation benefits and Surrogate Safety Assessment Model (SSAM) developed by Siemens was used to analyze the safety gains due to installation of dual right-turn lanes.

Download or read book Federally Coordinated Program of Highway Research Development and Technology written by and published by . This book was released on 1983 with total page 838 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Impacts on Safety of Left turn Treatment at High Speed Signalized Intersections written by T. H. Maze and published by . This book was released on 1994 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: Left-turning traffic is a major source of conflicts at intersections. Though an average of only 10% to 15% of all approach traffic turns left, these vehicles are involved in approximately 45% of all accidents. This report presents the results of research conducted to develop models which estimate approach accident rates at high speed signalized intersections. The objective of the research was to quantify the relationship between traffic and intersection characteristics, and accident potential of different left turn treatments. Geometric, turning movement counts, and traffic signal phasing data were collected at 100 intersections in Iowa using a questionnaire sent to municipalities. Not all questionnaires resulted in complete data and ultimately complete data were derived for 63 intersections providing a database of 248 approaches. Accident data for the same approaches were obtained from the Iowa Department of Transportation Accident Location and Analysis System (ALAS). Regression models were developed for two different dependent variables: 1) the ratio of the number of left turn accidents per approach to million left turning vehicles per approach, and 2) the ratio of accidents per approach to million traffic movements per approach. A number of regression models were developed for both dependent variables. One model using each dependent variable was developed for intersections with low, medium, and high left turning traffic volumes. As expected, the research indicates that protected left turn phasing has a lower accident potential than protected/permitted or permitted phasing. Left turn lanes and multiple lane approaches are beneficial for reducing accident rates, while raised medians increase the likelihood of accidents. Signals that are part of a signal system tend to have lower accident rates than isolated signals. The resulting regression models may be used to determine the likely impact of various left turn treatments on intersection accident rates. When designing an intersection approach, a traffic engineer may use the models to estimate the accident rate reduction as a result of improved lane configurations and left turn treatments. The safety benefits may then be compared to any costs associated with operational effects to the intersection (i.e., increased delay) to determine the benefits and costs of making intersection safety improvements.

Download or read book Federally Coordinated Program of Highway Research Development and Technology Annual Progress Report Fiscal Year 1985 written by and published by . This book was released on 1986 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of Warrants for Left turn Phasing written by Kenneth R. Agent and published by . This book was released on 1976 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Federally Coordinated Program of Highway Research and Development written by United States. Federal Highway Administration and published by . This book was released on with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Right turn Traffic Volume Adjustment in Traffic Signal Warrant Analysis written by Cui Zhou and published by . This book was released on 2016 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation was based on the research project, Right-Turn Traffic Volume Adjustment in Traffic Signal Warrants, sponsored by the Nevada Department of Transportation (NDOT). Right-turn traffic does not affect intersection performance in the same magnitude as through or left-turn traffic. Therefore, it is necessary to apply an adjustment to the right-turn volume when conducting signal warrant analysis. Without any reduction, an intersection with heavy right-turn volume might mislead the signal warrant analysis result, and could make a difference in whether a signal is deemed warranted or not. Firstly, a comprehensive literature review was conducted focused on the state-of-the-practice on handling minor-street right-turn volumes while conducting signal warrant studies. Further, an agency survey at the Institute of Transportation Engineers (ITE) community discussion was performed to acquire valuable information from practicing engineers. It was found that the limited guidance in the Manual of Uniform Traffic Control Devises (MUTCD) is not sufficient to provide a clear direction on determining whether or how much right turns impact the signal warrant analysis. In reality, most traffic engineers have done the reduction based on engineering judgments by incorporating key factors such as geometry and main street volume. Sometimes agencies develop and adopt internal procedures but do not necessarily publish them. Based on the lack of an adequate guideline, a new one is needed to estimate the reduction factor for right-turn traffic on the minor street when conducting a traffic signal warrant study. The proposed guideline is based on the delay equivalent relationship between right-turn and through traffic. The right-turn volume equals an equivalent number of through vehicles, which would produce the same control delay on the minor street. The equivalent factor is defined as the measurement of the reduction of right turns. Because equivalent factors are calculated based on delay, it incorporates major impact factors of the right-turn and through traffic inherently, such as flow rates, conflicting flow rates, capacity, critical headways, and follow-up headways. Especially, the volume ratio in the two directions of the main street is considered. The research found that uneven volume distribution has a greater impact on the right-turn movement on the minor street. Therefore, just considering the main street volume can cause over- or under-estimation of the impact of the main street traffic on the minor street. Further, regression models were developed for all the configurations with calibrated regression coefficients. The advantage of these models is that they could give an equivalent factor for a specific volume scenario. The proposed guidelines were tested at three intersections and the results indicated that it is convenient to use and easily help to determine right-turn volume equivalents. At last, pedestrian impact on right-turn traffic adjustment was discussed. Usually, pedestrians crossing the main street would block right-turn vehicles on the minor street, and on the other hand, the through vehicles on the minor street can use this gap to cross an intersection. A Monte Carlo model was built to simulate the real operation of two-way stop-control (TWSC) intersections, and further validated with field data that was collected at one intersection near the University of Nevada, Reno (UNR) campus. With this model, minor-street through capacity considering pedestrian crossings was estimated. Using this enlarged capacity allows accurate calculation of equivalent factors by considering the counter impact of pedestrians on right turns. In summary, this research focused on the right-turn adjustment in the signal warrant. The decision of reducing the right turns on the minor street is somewhat subjective. Therefore, this study developed a practical guidance for determining the percentage of right turns to be considered in the signal warrant analysis. Based on the data analysis and case study results, statewide uniform guidelines were developed for implementation in the State of Nevada.

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1992 with total page 1246 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of Warrants for Left turn Lanes written by Kenneth R. Agent and published by . This book was released on 1979 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Left Turn Signal Warrants for Arizona written by J. S. Matthias and published by . This book was released on 1985 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: A warrant was developed to choose the appropriate type of left turn signal phasing: permissive, exclusive/permissive, or exclusive. Time-lapse photography was used to observe volume and delay data at a total of six arterial-arterial signalized intersections in the Phoenix metropolitan area. From the time-lapse film, data on volume, number of vehicles stopping, total delay, average delay per stopped vehicle, and average delay for all vehicles was obtained for each turning movement. The effect of the type of left turn signal phasing on left turn delay and through delay was analyzed. A three year history of Accident rates for the three types of left turn phasing were also reviewed. The developed warrant chooses the type of left turn phasing based on left turn volume, opposing volume, number of opposing lanes, cycle length, approach speed, sight distance restrictions, and accident history. (Author)

Download or read book Highway Research and Development Studies Using Federal aid Research and Planning Funds written by and published by . This book was released on 1964 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt: