Download or read book Improved Pedestrian Safety at Signalized Intersections Operating the Flashing Yellow Arrow written by David S. Hurwitz and published by . This book was released on 2013 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: In some jurisdictions, protected left-turn phasing has been replaced with the flashing yellow arrow (FYA) for protected/permissive left turns (PPLTs) to reduce delay. However, it is important to have a thorough understanding of the conflict between pedestrians and the permissive left-turning vehicle. This presentation summarizes the results of research conducted with a high-fidelity, motion-based driving simulator and mobile eye-tracking equipment to study the effects of the opposing traffic, the presence and walking direction of pedestrians, and the number of section heads to display the FYA on driver performance. To accomplish this research, a six-intersection simulated environment was created. In total, 27 subjects completed the course, allowing the analysis of 620 permissive left-turn maneuvers. Eye-glance durations for the intersection approach and turning maneuver were captured for left-turn pavement bay markings, the signal indication, the pedestrian and vehicle waiting area, and the pedestrian signal heads. The total glance durations for each of these areas were analyzed. The following results were obtained: 1) the increased presence of pedestrians led drivers to focus more attention on these crossing pedestrians; 2) as the number of opposing vehicles increased, drivers spent less time fixating on pedestrians; 3) Four to seven percent of drivers did not focus on pedestrians in the crosswalk; and 4) there did not appear to be a difference between any variable and the presence of a three- or four-section head. In terms of practice, the results suggest that it may be desirable to limit the permissive operation when pedestrians are present. Moreover, the findings may indicate that the additional cost of four-section heads is not justified.

Download or read book Pedestrian Safety at Signalized Intersections Operating the Flashing Yellow Arrow written by Halston Tuss and published by . This book was released on 2012 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: At signalized intersections, pedestrians are considered to be amongst the most vulnerable. When in the crosswalk at intersections without protected left-turn phasing, pedestrians are particularly at risk from left-turning vehicles. Until recently, a wide variety of indications were in use across the US to indicate a permissive left-turn condition to the driver. In Oregon, the Flashing Yellow Arrow (FYA) has been used to indicate the permissive left-turn condition for approximately 10 years. With the addition of the FYA in the 2009 MUTCD, it is likely that its use will continue to increase nationally. Though many operational and safety issues have been studied about the FYA indication, this research proposes to fully investigate factors that influence driver behavior in the context of the permissive left-turn conflict with pedestrians. Specifically, the research seeks to study driver glance behavior to identify reasons why drivers are, "looking at but not seeing" pedestrians in or near the crosswalk or not searching for the presence of pedestrians at all.

Download or read book Safety Evaluation of Flashing Yellow Arrow at Signalized Intersections written by Raghavan Srinivasan (Transportation engineer) and published by . This book was released on 2020 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study evaluated the safety effect of the flashing yellow arrow (FYA) treatment at signalized intersections. The major objective of this strategy is to reduce the frequency of left-turn (LT) crashes, especially those that involve a collision between left turns and vehicles traveling straight through from the opposite direction. The project team conducted an empirical Bayes before-after analysis of installations in Nevada, North Carolina, Oklahoma, and Oregon. The treatments were divided into seven categories depending on the phasing system in the before and after periods, number of roads where FYAs were implemented, and number of legs at each intersection. The first five categories involved permissive or protected-permissive phasing in the before period. Intersections in these five treatment categories experienced a reduction in the primary target crashes under consideration: LT crashes and left-turn-with-opposing-through (LTOT) crashes at the intersection level. The reduction ranged from 15 to 50 percent depending on the treatment category. Intersections in categories 6 and 7 had at least one protected LT phase in the before period, and after phasing had an FYA protected-permissive LT phase without time-of-day operation (category 6) and with time-of-day operation (category 7). Consistent with results from previous studies, these intersections experienced an increase in LT and LTOT crashes. The B/C ratios for categories 1-5 ranged from 56:1 to 144:1.

Download or read book Safety Evaluation of Flashing Yellow Arrow at Signalized Intersections written by Raghavan Srinivasan and published by . This book was released on 2021 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study evaluated the safety effect of the flashing yellow arrow (FYA) treatment at signalized intersections. The major objective of this strategy is to reduce the frequency of left-turn (LT) crashes, especially those that involve a collision between left turns and vehicles traveling straight through from the opposite direction. The project team conducted an empirical Bayes before-after analysis of installations in Nevada, North Carolina, Oklahoma, and Oregon. The treatments were divided into seven categories depending on the phasing system in the before and after periods, number of roads where FYAs were implemented, and number of legs at each intersection. The first five categories involved permissive or protected-permissive phasing in the before period. Intersections in these five treatment categories experienced a reduction in the primary target crashes under consideration: LT crashes and left-turn-with-opposing-through (LTOT) crashes at the intersection level. The reduction ranged from 15 to 50 percent depending on the treatment category. Intersections in categories 6 and 7 had at least one protected LT phase in the before period, and after phasing had an FYA protected-permissive LT phase without time-of-day operation (category 6) and with time-of-day operation (category 7). Consistent with results from previous studies, these intersections experienced an increase in LT and LTOT crashes. The B/C ratios for categories 1-5 ranged from 56:1 to 144:1.

Download or read book Direct and Indirect Effect of the Flashing Yellow Arrow Signal for Left turn Traffic on Safety at Signalized Intersections written by Khamar Salma Chittoor Khader and published by . This book was released on 2011 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: develop safety performance functions (for left-turn as well as total number of crashes). The estimated number of left-turn and total number of crashes, had FYA signals not been installed, were then compared to the actual number of left-turn and total number crashes that occurred at the study intersections.Negative Binomial (log-link) distribution was observed to be a better fit to develop safety performance functions than Poisson (log-link) distribution. The results obtained indicate that FYA signals, in general, help reduce left-turn crashes (direct effect) as well as the total number of crashes (indirect effect) and contribute to improved safety at signalized intersections. They do not seem to be suitable for intersections with heavy-traffic volume.

Download or read book Safety Evaluation of Flashing Yellow Arrows for Protected permissive Left turn Control written by Hasan Ozer and published by . This book was released on 2016 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Urban Intersection Improvements for Pedestrian Safety written by C. M. Abrams and published by . This book was released on 1976 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Safety Evaluation of Flashing Yellow Arrows at Signalized Intersections written by Raghavan Srinivasan and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study evaluated the safety effect of the flashing yellow arrow (FYA) treatment at signalized intersections. The major objective of this strategy is to reduce the frequency of left-turn (LT) crashes, especially those that involve a collision between and vehicles traveling straight through from the opposite direction.--Abstract.

Download or read book Urban Intersection Improvements for Pedestrian Safety Identification of safety and operational problems at intersections written by and published by . This book was released on 1977 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Urban Intersection Improvements for Pedestrian Safety written by and published by . This book was released on 1977 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Safety evaluation of flashing yellow arrows at signalized intersections written by and published by . This book was released on 2020 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Use of Traffic Conflicts to Estimate Vehicle pedestrian Safety at Signalized Intersections written by Hiba Nassereddine and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding how vehicle drivers and pedestrians interact is key to identifying countermeasures that improve the safety of the interactions. As a result, techniques that can be used to evaluate the effectiveness of traffic control device-based safety countermeasures without the need to wait for the availability of crash data are needed. Using video data, the interactions between right-turning vehicles and conflicting pedestrians were documented for sites with a permissive circular green indication or a flashing yellow arrow (FYA) permissive right turn indication and quantified using vehicle and pedestrian position timestamps. Multiple non-probabilistic linear regression models were created to describe the relationship between the position of the pedestrian within the crosswalk and the time for a right turning vehicle maneuver to be completed. Given the nature of the models output, a Pedestrian Respect Indicator (PRI) is introduced as an indicator of the safety of vehicle-pedestrian interactions. The higher the PRI, the more "respect" towards pedestrians. Surrogate safety measures (SSMs) have allowed to step away from traditional approach and analyze safety performance without relying on crash records. In recent years, the use of surrogate measures to estimate crash probabilities with extreme value theory (EVT) models has been an alternative approach to its use as aggregate crash frequency predictors. Univariate and bivariate extreme value theory models were developed using the block maxima (BM) approach and the peak over threshold (POT) approach. In addition, Bayesian hierarchical models were developed for each approach. Using the resulting estimates, the number of crashes was estimated for each model. The estimated crashes from the Bayesian hierarchical models were closer to the observed number of crashes than those from other models. Time to complete a turn produced better fit models indicating that the time to complete a turn is a good representation of traffic interactions. Obtaining SSMs from video data requires complex processing and large video data sizes. A software-based framework to estimate SSMs, such as PET and time-to-collision (TTC) values between right-turn-on-red (RTOR) and through vehicles was proposed and it demonstrated the feasibility of using vehicle trajectories obtained from existing radar-based vehicle detection systems to calculate such measures.

Download or read book An Evaluation of Effectiveness of Flashing Yellow Arrow Signal for Left turns written by Kailas Venkitasubramanian and published by . This book was released on 2008 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis evaluated the effectiveness of flashing yellow arrow (FYA) permitted left-turn signals in reducing conflicts and events at intersections. A FYA permissive signal is a recent treatment used as an alternate to circular green signal at signalized intersections. It is the newest addition to the series of permitted left-turn signal indicators and has been designed to improve the clarity of indication among drivers. The signal is expected to result in safer turning movements during the permitted phase. Conflict data was collected during morning peak period (7:00 AM to 9:00 AM) and evening peak period (4:00 PM to 8:00 PM) at four study intersections in Charlotte. Data was collected before the installation of FYA signal was introduced and after one month, three months and six months of installation of FYA. Relevant types of conflicts and events associated with left-turn maneuver were observed and recorded. Descriptive statistics, proportions of conflicts/events and statistical tests were conducted to analyze the data collected. Conflicts and events were also analyzed separately for each intersection using various comparison sets to understand their trend over time and the impact of FYA on them. Observations and analysis indicated that benefits in terms of reduction in conflicts and events are substantial at 7th Street / 5th Street intersection and Mallard Creek Church Road / 1-85 Southbound interchange but are marginal and currently statistically insignificant at Sunset Road / 1-77 interchanges. Overall, FYA leaves a positive effect on the intersection safety, helps reduce vehicular conflicts/events and is suitable for application at other intersections in the future.

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 Traffic Engineering Handbook written by ITE (Institute of Transportation Engineers) and published by John Wiley & Sons. This book was released on 2016-01-26 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt: Get a complete look into modern traffic engineering solutions Traffic Engineering Handbook, Seventh Edition is a newly revised text that builds upon the reputation as the go-to source of essential traffic engineering solutions that this book has maintained for the past 70 years. The updated content reflects changes in key industry standards, and shines a spotlight on the needs of all users, the design of context-sensitive roadways, and the development of more sustainable transportation solutions. Additionally, this resource features a new organizational structure that promotes a more functionally-driven, multimodal approach to planning, designing, and implementing transportation solutions. A branch of civil engineering, traffic engineering concerns the safe and efficient movement of people and goods along roadways. Traffic flow, road geometry, sidewalks, crosswalks, cycle facilities, shared lane markings, traffic signs, traffic lights, and more—all of these elements must be considered when designing public and private sector transportation solutions. Explore the fundamental concepts of traffic engineering as they relate to operation, design, and management Access updated content that reflects changes in key industry-leading resources, such as the Highway Capacity Manual (HCM), Manual on Uniform Traffic Control Devices (MUTCD), AASSHTO Policy on Geometric Design, Highway Safety Manual (HSM), and Americans with Disabilities Act Understand the current state of the traffic engineering field Leverage revised information that homes in on the key topics most relevant to traffic engineering in today's world, such as context-sensitive roadways and sustainable transportation solutions Traffic Engineering Handbook, Seventh Edition is an essential text for public and private sector transportation practitioners, transportation decision makers, public officials, and even upper-level undergraduate and graduate students who are studying transportation engineering.

Download or read book Evaluating the Effectiveness of Conversion of Traditional Five Section Head Signal to Flashing Yellow Arrow FYA Signal written by Meshal Ibrahim Almoshaogeh and published by . This book was released on 2014 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the United States, there are two schemes of operating traffic signal controls for permitted protected left turns (PPLT) namely the traditional five-section head system (known as Dog-House) and the flashing yellow arrow system (FYA). Past studies have agreed that these controls lead to decrease the average delay per left turn vehicle, decrease the protected green time, increase the left turn capacity, and enhance the intersection overall operation. The flashing yellow arrow (FYA) has been approved by the Federal Highway Administration as the national standard for the PPLT operations at signalized intersections. So, the Florida Department of Transportation also approved this new system and they are extensively replacing the traditional system with the new system on the area of Central Florida (Lin, et al, 2010). Both these systems have been used for a long time and there are some studies that evaluated these systems but there are limited number of projects that evaluated and/or compared between the two PPLT systems from the operational perspective.

Download or read book Urban intersection improvements for pedestrian safety written by Roger G. Petzold and published by . This book was released on 1977 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: