Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Download Safety Performance Evaluation Of Intersection Traffic And Safety Assets full books in PDF, epub, and Kindle. Read online Safety Performance Evaluation Of Intersection Traffic And Safety Assets ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Author : Han Gyol Kim
Publisher :
ISBN 13 :
Total Pages : 168 pages
Book Rating : 4.:/5 (859 download)
Download or read book Safety Performance Evaluation of Intersection Traffic and Safety Assets written by Han Gyol Kim and published by . This book was released on 2012 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Liteng Zha
Publisher :
ISBN 13 :
Total Pages : 62 pages
Book Rating : 4.:/5 (895 download)
Download or read book Next Generation Safety Performance Monitoring at Signalized Intersections Using Connected Vehicle Technology written by Liteng Zha and published by . This book was released on 2014 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: Crash-based safety evaluation is often hampered by randomness, lack of timeliness, and rarity of crash occurrences. Surrogate safety data are commonly used as an alternative to crash data; however, its current practice is still resource intensive and prone to human errors. The advent of connected vehicle technology allows vehicles to communicate with each other as well as infrastructure wirelessly. Through this platform, vehicle movements and signal status at the facilities can be automatically and continually monitored in real time. This study explores the viability of long-term safety performance evaluation at signalized intersection using connected vehicle technology. The development focuses on vehicle-to-infrastructure (V2I) communications which require one road-side equipment (RSE) and some level of on-board equipment to be successful. To accomplish the objective, the researchers defined useful safety measures and developed specific algorithms to derive them in real time from the V2I communication data sets. The safety measures were categorized into single-OBE measures and dual-OBE measure based on the number of the equipped vehicle needed to be monitored. We used vehicles trapped in dilemma zone as the single-OBE measure. The dual-OBE measures included rear-end and crossing conflicts. Different simulation scenarios were designed in VISSIM to test the effectiveness of the proposed framework, effect of market penetration rate as well as required observation period for effective implementation. The evaluation results indicated that the application can effectively detect changes in safety performance at full market penetration. It can detect a shift of crash pattern from rear-end crashes to right-angle crashes due to the shorted inter green interval at low traffic volume as well as the mitigation of this pattern during the medium-to-high traffic volume. The selected measures can also identify the increasing risk of rear-end and right-angle crashes after removing advance detectors at the major approaches. Sensitivity analysis from the 60 simulation hours' data showed that more than 40% and 60% penetration rate is likely to be required for a reliable detection in the low volume level and medium-to-high volume level, respectively. Increase of traffic volume activated the corresponding phases more frequently and may result in fewer safety measures being collected. Although losing the power of detection, single-OBE measure was demonstrated to be more reliable at lower penetration rate. Under low OBE market penetrations, observation period can be extended to compensate for small sample size. However, the required observation periods vary with the types of safety indicators being collected and the levels of OBE saturation. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/152565
Author : Young-Jun Kweon
Publisher :
ISBN 13 :
Total Pages : 86 pages
Book Rating : 4.:/5 (1 download)
Download or read book Development of a Safety Evaluation Procedure for Identifying High-risk Signalized Intersections in the Virginia Department of Transportation's Northern Virginia District written by Young-Jun Kweon and published by . This book was released on 2007 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research was undertaken to develop an evaluation procedure to identify high-risk four-legged signalized intersections in VDOT's Northern Virginia district by traffic movements and times of day. By using the developed procedure, traffic engineers are expected to be able to identify signalized intersections where the traffic crash occurrences under different traffic conditions for different times of day are more frequent than would normally be expected. Using generalized linear models such as negative binomial models, one safety performance function was estimated for each of nine crash population reference groups formed by three traffic crash patterns (crash patterns 1, 4, and 6) and four times of day (A.M. peak, mid day, P.M. peak, and evening off peak). Crash pattern 1 is a same-direction crash (rear-end, sideswipe or angle crash) that occurs after exiting the intersection; crash pattern 4 is a right-angle crash between two adjacent straight-through vehicle movements in the intersection; and crash pattern 6 is an angle or head-on or opposite sideswipe crash between a straight-through vehicle movement and an opposing left-turn vehicle movement in the intersection. The procedure developed in this study is based on the empirical Bayes (EB) method. Additional data do not need to be collected in order to use the EB procedure because all the data required for applying the EB procedure should be obtainable from VDOT's crash database and from Synchro input data that are already available to traffic engineers for traffic signal phase plans. Thus, the EB procedure is cost-effective and readily applicable. For easy application of the EB procedure, an EB spreadsheet was developed using Microsoft Excel, and a users' guide was prepared. These are available from the author upon request.
Author : Jarvis Dale Michie
Publisher : Transportation Research Board National Research
ISBN 13 :
Total Pages : 1146 pages
Book Rating : 4.3/5 (555 download)
Download or read book Recommended Procedures for the Safety Performance Evaluation of Highway Appurtenances written by Jarvis Dale Michie and published by Transportation Research Board National Research. This book was released on 1981 with total page 1146 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Adam J. Kirk
Publisher :
ISBN 13 :
Total Pages : 108 pages
Book Rating : 4.:/5 (869 download)
Download or read book Development of a Design Based Intersection Safety Performance Evaluation Tool written by Adam J. Kirk and published by . This book was released on 2013 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Saeed Niknejad
Publisher : CreateSpace
ISBN 13 : 9781515118176
Total Pages : 96 pages
Book Rating : 4.1/5 (181 download)
Download or read book Traffic Safety Evaluation by Converting Signalized Intersection to U-Turn written by Saeed Niknejad and published by CreateSpace. This book was released on 2015-07-20 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: Directional midblock median opening with Left-Turn Lanes and Loons between four-leg signalized intersections without median openings have been designed to smooth flow of traffic especially on Main Street. Since 2004, there has been growing interest in their potential benefits as raising mental capacity of drivers due to flow instead of stop by traffic signal. This interest has created a need for data regarding the safety effect of U-Turns. In this dissertation, the effect on u-turns crashes of converting signalized intersection in Tehran from traffic signal removal to install Directional midblock median was estimated. The six such conversions were studied in this research. Safety analysis of u-turns conversions was done by using Before -After study and modeling of U-turns crashes with statistics methods. An Empirical Bayesian (EB) procedure was used to evaluate safety of u-turns conversions. In addition, the history of accidents was studied in both period of before and after treatment.
Author : Nicholas J. Garber
Publisher :
ISBN 13 :
Total Pages : 68 pages
Book Rating : 4.:/5 (1 download)
Download or read book Safety Performance Functions for Intersections on Highways Maintained by the Virginia Department of Transportation written by Nicholas J. Garber and published by . This book was released on 2010 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, significant effort and money have been invested through research and implemented safety projects to enhance highway safety in Virginia. However, there is still substantial room for improvement in both crash frequency and severity. As there are limits in the available funds for safety improvements, it is crucial that allocated resources for safety improvement be spent at highway locations that will result in the maximum safety benefits. In addition, intersection crashes play a significant role in the safety conditions in Virginia. For example, crashes at intersections in Virginia for the period 2003 through 2007 account for 43.8% of all crashes and 26% of fatal crashes. Therefore, identifying intersections for safety improvements that will give the highest potential for crash reduction when appropriate safety countermeasures are implemented will have a significant impact on the overall safety performance of roads in Virginia. The Federal Highway Administration (FHWA) has developed a procedure for identifying highway locations that have the highest potential for crash reduction (ITT Corporation, 2008). A critical component of this method is the use of safety performance functions (SPFs) to determine the potential for crash reductions at a location. An SPF is a mathematical relationship (model) between frequency of crashes by severity and the most significant causal factors on a specific highway. Although the SafetyAnalyst User's Manual presents several SPFs for intersections, these were developed using data from Minnesota. FHWA also suggested that if feasible, each state should develop its own SPFs based on crash and traffic volume data from the state, as the SPFs that are based on Minnesota data may not adequately represent the crash characteristics in all states. SPFs for intersections in Virginia were developed using the annual average daily traffic as the most significant causal factor, emulating the SPFs currently suggested by SafetyAnalyst. The SPFs were developed for both total crashes and combined fatal plus injury crashes through generalized linear modeling using a negative binomial distribution. Models were also developed for urban and rural intersections separately, and in order to account for the different topographies in Virginia, SPFs were also developed for three regions: Northern, Western, and Eastern. This report covers Phases I and II of the study, which includes urban and rural intersections maintained by VDOT. Statistical comparisons of the models based on Minnesota data with those based on the Virginia data showed that the specific models developed for Virginia fit the Virginia crash data better. The report recommends that VDOT's Traffic Engineering Division use the SPFs developed for Virginia and the specific regional SPFs suggested in this report to prioritize the locations in need of safety improvement.
Download or read book Traffic Safety Evaluation Research Review written by and published by . This book was released on 1984 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Thanh Le (Highway engineer)
Publisher :
ISBN 13 :
Total Pages : 92 pages
Book Rating : 4.:/5 (14 download)
Download or read book Safety Evaluation of Multiple Strategies at Signalized Intersections written by Thanh Le (Highway engineer) and published by . This book was released on 2018 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Evaluates multiple low-cost safety improvements at signalized intersections for bacis signing, pavement marking, and signal enhancements.
Author : Raghavan Srinivasan
Publisher : Transportation Research Board
ISBN 13 : 0309213452
Total Pages : 48 pages
Book Rating : 4.3/5 (92 download)
Download or read book Evaluation of Safety Strategies at Signalized Intersections written by Raghavan Srinivasan and published by Transportation Research Board. This book was released on 2011 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB’s National Cooperative Highway Research Program (NCHRP) Report 705: Evaluation of Safety Strategies at Signalized Intersections explores crash modification factors (CMFs) for safety strategies at signalized intersections. CMFs are a tool for quickly estimating the impact of safety improvements.
Author : Christopher Michael Monsere
Publisher :
ISBN 13 :
Total Pages : 11 pages
Book Rating : 4.:/5 (114 download)
Download or read book Research Project Work Plan for Assessment of Statewide Intersection Safety Performance written by Christopher Michael Monsere and published by . This book was released on 2008 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author :
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (759 download)
Download or read book Assessment of Statewide Intersection Safety Performance written by and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Harold L. Michael
Publisher :
ISBN 13 :
Total Pages : 464 pages
Book Rating : 4.3/5 (91 download)
Download or read book Evaluation of Design and Control Alternatives to Improve Safety of Intersections of Multi-lane Highways with Other Highways written by Harold L. Michael and published by . This book was released on 1981 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: Analysis of 18 high accident intersections in Indiana.
Author : Ahmed Abdelrahman
Publisher :
ISBN 13 :
Total Pages : 54 pages
Book Rating : 4.:/5 (119 download)
Download or read book Safety Evaluation of Innovative Intersection Designs written by Ahmed Abdelrahman and published by . This book was released on 2020 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: The results showed that this alternative design could provide much benefits in terms of its operational performance. However, its poor safety performance could result in losses much higher than its benefits. The study concludes that DDIs could significantly decrease crash frequency, while DLTs could not provide safety benefits. However, DLTs might be more efficient for operational performance. It is recommended that appropriate safety countermeasures should be developed and implemented to enhance traffic safety at DLTs.
Download or read book Safety Evaluation of Intersections Using Traffic Conflicts written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Douglas W. Harwood
Publisher :
ISBN 13 :
Total Pages : 204 pages
Book Rating : 4.3/5 (91 download)
Download or read book Prediction of the Expected Safety Performance of Rural Two-lane Highways written by Douglas W. Harwood and published by . This book was released on 2000 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents an algorithm for predicting the safety performance of a rural two-lane highway. The accident prediction algorithm consists of base models and accident modification factors for both roadway segments and at-grade intersections on rural two-lane highways. The base models provide an estimate of the safety performance of a roadway or intersection for a set of assumed nominal or base conditions. The accident modification factors adjust the base model predictions to account for the effects on safety for roadway segments of lane width, shoulder width, shoulder type, horizontal curves, grades, driveway density, two-way left-turn lanes, passing lanes, roadside design and the effects on safety for at-grade intersections of skew angle, traffic control, exclusive left- and right-turn lanes, sight distance, and driveways. The accident prediction algorithm is intended for application by highway agencies to estimate the safety performance of an existing or proposed roadway. The algorithm can be used to compare the anticipated safety performance of two or more geometric alternatives for a proposed highway improvement. The accident prediction algorithm includes a calibration procedure that can be used to adapt the predicted results to the safety conditions encountered by any particular highway agency on rural two-lane highways. The algorithm also includes an Empirical Bayes procedure that can be applied to utilize the safety predictions provided by the algorithm together with actual site-specific accident history data.
Author : Thanh Le (Highway engineer)
Publisher :
ISBN 13 :
Total Pages : 88 pages
Book Rating : 4.:/5 (13 download)
Download or read book Safety Evaluation of Multiple Strategies at Stop-controlled Intersections written by Thanh Le (Highway engineer) and published by . This book was released on 2018 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Development of Crash Modification Factors program studied the safety performance of various stop-controlled intersections for the Evaluation of Low-Cost Safety Improvements Pooled Fund Study. This study evaluated the safety effectiveness of multiple low-cost treatments at stop-controlled intersections. Improvements included basic signing and pavement markings. This strategy is intended to reduce the frequency and severity of crashes at stop-controlled intersections by alerting drivers to the presence and type of approaching intersection. Geometric, traffic, and crash data were obtained at three- and four-legged, two- and four-lane major road, and urban and rural stop-controlled intersections in South Carolina. To account for potential selection bias and regression to the mean, an empirical Bayesian before-after analysis was conducted, using reference groups of untreated intersections with similar characteristics to the treated sites. The analysis also controlled for changes in traffic volumes throughout time and time trends in crash counts unrelated to the treatments. The aggregate results indicate reductions for all crash types analyzed (i.e., total, fatal and injury, rear-end, right-angle, and nighttime). The reductions are statistically significant at the 95-percent confidence level for all crash types. For all crash types combined, the crash modification factors (CMFs) are 0.917 for all severities and 0.899 for fatal and injury crashes. The CMFs for rear-end, right-angle, and nighttime crashes are 0.933, 0.941, and 0.853, respectively. The benefit-cost ratio estimated with conservative cost and service life assumptions is 12.4 to 1 for total crashes at unsignalized intersections. The results suggest that the multiple low-cost treatments, even with conservative assumptions on cost, service life, and the value of a statistical life, can be cost effective.
