Evaluation of the Flashing Yellow Arrow (FYA) Permissive Left-Turn in Shared Yellow Signal Sections

2014 ◽  
Author(s):  
David A. Noyce ◽  
Andrea R. Bill ◽  
Jr. Michael A. ◽  
◽  
◽  
...  
Keyword(s):  
Left Turn ◽  
Flashing Yellow Arrow ◽  
Yellow Arrow

Safety effects of traffic signing for left turn flashing yellow arrow signals

2015 ◽  
Vol 75 ◽  
pp. 252-263 ◽  
Author(s):  
Kerrie L. Schattler ◽  
Cody J. Gulla ◽  
Travis J. Wallenfang ◽  
Beau A. Burdett ◽  
Jessica A. Lund
Keyword(s):  
Left Turn ◽  
Flashing Yellow Arrow ◽  
Yellow Arrow

Safety Performance of Flashing Yellow Arrow for Protected–Permissive Left-Turn Signal Control in Central Illinois

2017 ◽  
Vol 2636 (1) ◽  
pp. 32-42 ◽  
Author(s):  
Kerrie L. Schattler ◽  
Eric P. Anderson ◽  
Trevor Hanson
Keyword(s):  
Empirical Bayes ◽  
Safety Evaluation ◽  
Left Turn ◽  
Turn Signal ◽  
Crash Data ◽  
Flashing Yellow Arrow ◽  
Before And After ◽  
Control Research ◽  
Central Illinois ◽  
Yellow Arrow

In 2010, the Illinois Department of Transportation began implementing the flashing yellow arrow (FYA) at intersections operating with protected–permissive left-turn (PPLT) control. Research was conducted to evaluate the safety-effectiveness of FYAs at 86 intersections and 164 approaches in central Illinois. The effectiveness evaluation was performed with 3 years of before-and-after FYA installation crash data and the empirical Bayes method. In the before condition, the left-turn signals operated with a circular green display indicating the permissive interval of PPLT control using a five-section signal head. In the after condition, the FYA replaced the circular green display for the permissive interval of PPLT with a four-section signal head. Supplemental traffic signs were mounted on the mast arm adjacent to the left-turn signal at over half of the FYA installations. The results of the comprehensive safety evaluation of the FYA for PPLT control are presented. Analyses were also performed to assess the effects of the FYA supplemental signs and the effects of the FYA overall on two subsets of at-fault drivers: older drivers (age 65+) and younger drivers (age 16 to 21). The resulting mean crash modification factors for the targeted crash types ranged from 0.589 to 0.714. The findings of this research support the continued use of FYAs for PPLT control to improve safety at signalized intersections in central Illinois.

scholarly journals Permissive Left-Turn Behavior at the Flashing Yellow Arrow in the Presence of Pedestrians

2013 ◽  
Author(s):  
Patrick Marnell ◽  
Halston Tuss ◽  
David Hurwitz ◽  
Kirk Paulsen ◽  
Chris Monsere
Keyword(s):  
Left Turn ◽  
Flashing Yellow Arrow ◽  
Yellow Arrow

Crash Modification Factors for the Flashing Yellow Arrow Treatment at Signalized Intersections

2018 ◽  
Vol 2672 (30) ◽  
pp. 142-152 ◽  
Author(s):  
Raghavan Srinivasan ◽  
Bo Lan ◽  
Daniel Carter ◽  
Sarah Smith ◽  
Kari Signor
Keyword(s):  
North Carolina ◽  
Empirical Bayes ◽  
Evaluation Method ◽  
Signalized Intersections ◽  
Left Turn ◽  
Flashing Yellow Arrow ◽  
Crash Modification Factors ◽  
Treatment Category ◽  
Using Data ◽  
Yellow Arrow

This paper presents the results of an evaluation of the flashing yellow arrow (FYA) treatment using data from signalized intersections in Nevada, North Carolina, Oklahoma, and Oregon. The evaluation method was an empirical Bayes before–after analysis. The treatments were divided into seven categories depending on the phasing system in the before period (permissive, protected–permissive, or protected), phasing system in the after period (FYA permissive or FYA protected–permissive), the number of roads where the FYA was implemented (one road or both roads), and the number of legs at the intersections (three or four). The first five treatment 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: left turn crashes and left turn with opposing through crashes. The reduction ranged from 15% to 50%, depending on the treatment category. Intersections that had at least one protected left turn phase in the before period and had FYA protected–permissive left turn phase in the after period experienced an increase in left turn crashes and left turn with opposing through crashes, indicating that replacing a fully protected left turn with FYA will likely cause an increase in left turn crashes.

Protected–permissive left turn phasing with flashing yellow arrow signal: study of red intervals for an effective phase transition

2019 ◽  
Vol 46 (8) ◽  
pp. 732-741
Author(s):  
Muqtasid Mahbub ◽  
Min-Wook Kang ◽  
Joyoung Lee
Keyword(s):  
Phase Transition ◽  
North America ◽  
Traffic Simulation ◽  
Transition Period ◽  
Conflict Analysis ◽  
The Other ◽  
Left Turn ◽  
Flashing Yellow Arrow ◽  
Effective Phase ◽  
Yellow Arrow

Protected–permissive left turn (PPLT) phasing has been popular and widely used in many urban intersections in North America because of its operational benefits. A significant number of intersections have recently been upgraded with four-section signal heads with flashing yellow arrow (FYA) indication for an effective protected–permissive left turn operation. The present study seeks to find appropriate length of two red intervals whose roles are important, but different during the transition period of FYA-PPLT phasing. One is a red interval for delayed-start of permissive left turn movements; the other is additional red interval for delayed-start of opposing through movements. Micro-traffic simulation and conflict analysis are explored to assess the effects of the red intervals on intersection efficiency and safety. A useful reference, which describes the balanced length of the two red intervals under varying traffic levels, is developed as a result.

Driving Simulators for Evaluation of Novel Traffic-Control Devices: Protected–Permissive Left-Turn Signal Display Analysis

2003 ◽  
Vol 1844 (1) ◽  
pp. 25-34 ◽  
Author(s):  
David A. Noyce ◽  
Christopher R. Smith
Keyword(s):  
Traffic Control ◽  
Driving Simulator ◽  
Driving Simulators ◽  
Left Turn ◽  
Flashing Yellow Arrow ◽  
Green Ball ◽  
Other Information ◽  
Control Devices ◽  
Research Show ◽  
Yellow Arrow

A study evaluated drivers’ comprehension of several experimental five-section protected–permissive left-turn (PPLT) signal displays. A full-scale driving simulator and static driver study were used. Study methods were compared while evaluating drivers’ comprehension and response to various combinations of five-section PPLT signal-display arrangements (horizontal, vertical, and cluster) and permissive left-turn indications (green ball, flashing red ball, flashing yellow ball, flashing red arrow, and flashing yellow arrow). The results showed that the type of five-section PPLT signal display arrangement has very little effect on driver comprehension of the permissive left-turn maneuver. The type of permissive indication used in five-section PPLT signal displays had a significant effect on driver comprehension, since the green ball, flashing yellow ball, and flashing yellow arrow were the best understood. When combining five-section PPLT signal-display arrangements and permissive indications, the five-section horizontal arrangement with a flashing-yellow-ball permissive indication had the highest level of driver comprehension. The lack of surrounding driving cues in the static driver study led to significantly higher fail-critical (serious) response rates. The green-ball permissive indication had a driver comprehension rate over 30% lower in the static study, clearly showing that drivers do not correctly comprehend the meaning of the green ball (assume it is protected) and use other information to make left-turn decisions while driving. The findings of this research show that driving simulation provides an effective study method and effectively replicates the actual driving environment. Simulators should be considered when conducting driver comprehension analyses.

Modifying Highway Capacity Manual Methodology for Inclusion of Flashing-Yellow-Arrow Delay and Suppression

2020 ◽  
Vol 2674 (12) ◽  
pp. 233-242
Author(s):  
Daniel J. Cook
Keyword(s):  
Sensitivity Analysis ◽  
Signalized Intersections ◽  
Signalized Intersection ◽  
Effective Strategy ◽  
Highway Capacity ◽  
Left Turn ◽  
Highway Capacity Manual ◽  
Flashing Yellow Arrow ◽  
Left Turns ◽  
Yellow Arrow

Dallas phasing is an effective strategy for increasing the efficiency of protected-permissive left turns (PPLTs) at signalized intersections, without creating left-turn traps. The flashing yellow arrow (FYA) is the most widely used PPLT signal indication when Dallas phasing is utilized. The Highway Capacity Manual (HCM) signalized intersection methodology currently contains guidance on how to handle PPLTs with Dallas phasing. At intersections with the FYA indication, some agencies have been using a feature known as FYA delay, which delays the FYA indication, usually by 1 to 4 s. More recently, some agencies have also began using another feature, which suppresses the FYA when a conflicting pedestrian phase is active. The HCM does not contain guidance on how to handle FYA delay or suppression. This research proposed modifications to the HCM signalized intersection methodology to address these two FYA strategies. A sensitivity analysis was conducted to check the reasonableness of the proposed modifications. The sensitivity analysis showed that the proposed modifications are reasonable and produced the expected results.

Evaluation of Flashing Yellow Arrow in Traffic Signal Displays with Simultaneous Permissive Indications

2005 ◽  
Vol 1918 (1) ◽  
pp. 46-55 ◽  
Author(s):  
Michael A. Knodler ◽  
David A. Noyce ◽  
Kent C. Kacir ◽  
Christopher L. Brehmer
Keyword(s):  
Traffic Control ◽  
Driving Simulator ◽  
Left Turn ◽  
Flashing Yellow Arrow ◽  
Research Findings ◽  
Computer Based ◽  
Control Devices ◽  
Common Application ◽  
Yellow Arrow ◽  
Comprehensive Study

The results of a comprehensive study on protected and permissive left-turn (PPLT) operations showed that the flashing yellow arrow (FYA) indication was an acceptable and recommended application for permissive left turns. As documented in NCHRP Report 493, an FYA permissive indication was recommended for implementation in the FHWA Manual on Uniform Traffic Control Devices for Streets and Highways (MUTCD). Research findings suggested that the FYA be implemented in an exclusive four-section vertical signal display centered over the left-turn lane, which differs from the most common application of PPLT signal displays. Many traffic engineers currently use a five-section clustered-arrangement shared signal head to meet MUTCD requirements of two signal heads per major approach. FYA implementation in the five-section display would require an interim retrofit requiring the FYA to be displayed simultaneously with the through-movement circular green (CG), circular yellow, or circular red indication. This research evaluated driver comprehension of the retrofit display and the resulting simultaneous indications by using a dynamic driving simulator and computer-based static experiments. A comparison of seven permissive left-turn scenarios featuring the CG or FYA permissive indications, or both, was completed. In total, 264 drivers evaluated 3,457 permissive left-turn scenarios. Results showed that simultaneous indications in the retrofit display did not affect the drivers’ understanding of the permissive indications. The drivers demonstrated an understanding of the yield requirement with simultaneous indications (with a 65% to 89% correct responses), providing evidence to suggest that the simultaneous indications would be suitable as an interim display to ease FYA implementation.

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