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.

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.

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

Evaluation of Driver Comprehension and Visual Attention of the Flashing Yellow Arrow Display for Permissive Right Turns

2019 ◽  
Vol 2673 (8) ◽  
pp. 397-407 ◽  
Author(s):  
Hisham Jashami ◽  
David S. Hurwitz ◽  
Christopher Monsere ◽  
Sirisha Kothuri
Keyword(s):  
Visual Attention ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Driving Simulator ◽  
Probit Model ◽  
Flashing Yellow Arrow ◽  
Different Response ◽  
Turning Maneuver ◽  
Yellow Arrow ◽  
Right Turns

This research explored driver comprehension and behaviors in Oregon with respect to right-turn signal displays focusing on the Flashing Yellow Arrow (FYA) in a driving simulator. A counterbalanced, factorial design was chosen to explore three independent variables: signal indication type and active display, length of the right-turn bay, and presence of pedestrians. Driver decision-making and visual attention were considered. Data were obtained from 46 participants (21 women, 25 men) turning right 736 times in 16 experimental scenarios. A Mixed-effects Ordered Probit Model and a Linear mixed model were used to examine the influence of driver demographics on observed performance. Results suggest that the FYA indication improves driver comprehension and behavioral responses to the permissive right-turn condition. When presented with the FYA indication in the presence of pedestrians, nearly all drivers exhibited caution while turning and yielding to pedestrians and stopping when necessary. For the same turning maneuver, drivers presented with a circular green (CG) indication were less likely to exhibit correct behavior. At least for Oregon drivers, another clear finding was a general lack of understanding of the steady red arrow (SRA) display for right turns. Most drivers assume the SRA indication requires a different response than the circular red (CR) and remain stopped during the entire red interval, thus resulting in efficiency losses. These findings suggest that transportation agencies could potentially improve driver yielding behavior and pedestrian safety at signalized intersections with high volumes of permissive right turns from exclusive right-turn lanes by using the FYA display in lieu of a steady CG display.

Operational Impacts of Protected-Permitted Right-Turn Phasing and Pavement Markings on Bicyclist Performance during Conflicts with Right-Turning Vehicles

2019 ◽  
Vol 2673 (4) ◽  
pp. 789-799
Author(s):  
Masoud Ghodrat Abadi ◽  
David S. Hurwitz
Keyword(s):  
Traffic Control ◽  
Safety Concern ◽  
Lateral Position ◽  
Signalized Intersections ◽  
Pavement Markings ◽  
Conflict Area ◽  
Flashing Yellow Arrow ◽  
Mixed Factorial Design ◽  
Operational Impacts ◽  
Yellow Arrow

Conflict between bicycles and right-turning vehicles on the approach to signalized intersections is a critical safety concern. To understand the operational implications of protected-permitted right-turn signal indications in conjunction with pavement markings on bicyclist performance, a full-scale bicycling simulator experiment was performed. Velocity and lateral position of bicyclists were evaluated during conflicts between bicycles and right-turning vehicles. A mixed factorial design was considered. Two within-subject factors were analyzed: the signal indication for right-turning vehicles with five levels (circular red, circular green, solid red arrow, solid green arrow, and flashing yellow arrow), and the pavement markings in the conflict area with two levels (white lane markings with no supplemental pavement color and white lane markings with solid green pavement applied in the conflict area). Additionally, the influence of gender as a between-subject variable was considered. Forty-eight participants (24 female) completed the experiment. Signal indications and pavement markings had statistically significant effects on bicyclist velocity and lateral position, but these effects varied at different factor levels. Additionally, during the conflicts, male participants were found to have higher velocity than female participants. This difference was not influenced by engineering treatments. The results provide guidance to transportation professionals about how traffic control devices could be applied to conflict areas on the approach to signalized intersections.

Queue-Based Guidance for Signalization Consideration at Two and Three-Legged Intersections

2019 ◽  
Vol 2673 (10) ◽  
pp. 416-426
Author(s):  
Shannon Warchol ◽  
Nagui Rouphail ◽  
Chris Vaughan ◽  
Brendan Kearns
Keyword(s):  
North Carolina ◽  
Traffic Control ◽  
Signalized Intersections ◽  
Data Driven ◽  
Left Turn ◽  
Minor Road ◽  
Adjustment Factors ◽  
Queue Lengths ◽  
Control Devices ◽  
A Minor

This research collected and analyzed gap acceptance in North Carolina to develop a data-driven method for determining the need for considering additional signalization analysis at intersections with fewer than four legs. This method can be used for movements that merge with or cross two lanes of oncoming traffic. It is intended to provide guidance and support to traffic engineers in their decision-making process. Charts are provided to determine the expected 95th percentile queue lengths for left-turn, right-turn, and U-turn movements crossing or merging with two lanes of conflicting traffic. This situation is typically present along four-lane roadways where a one-way primary movement opposes either a minor road right-turn movement or a left-turn movement, or in the case of a median U-turn opening. Adjustment factors to the conflicting flowrate were developed to account for the presence of upstream signalized intersections. This method less frequently recommends further signal consideration when compared with the Manual on Uniform Traffic Control Devices peak hour warrant, but is similar to the delay-based level of service D/E threshold for two-way stop-controlled intersections in HCM6 Chapter 19.

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 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.

Teenage Drivers’ Understanding of Traffic Control Devices

2000 ◽  
Vol 1708 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Garry L. Ford ◽  
Dale L. Picha
Keyword(s):  
Traffic Control ◽  
Warning Signs ◽  
Driver Education ◽  
Safe Driving ◽  
Left Turn ◽  
Pavement Markings ◽  
The Road ◽  
Control Devices ◽  
Traffic Control Devices ◽  
Teenage Drivers

Teenage drivers are involved in traffic crashes more often than any other driver group, and their fundamental knowledge of traffic control devices and rules of the road is extremely important in safe driving. Only limited data exist, however, on teenage drivers’ understanding of traffic control devices, and little research has been done on determining their comprehension thereof. Research was performed to document teenage drivers’ ability to understand 53 traffic control devices. These traffic control devices included 6 combinations of sign shape and color; 8 regulatory signs; 14 warning signs; 7 school, highway–railroad grade crossing, and construction warning signs; 7 pavement markings; and 11 traffic signals. Research results were then compared with previous comprehension studies to identify specific traffic control devices that the driving public continually misunderstands. In general, the results indicated that surveyed teenage drivers understood the traffic control devices to some degree. Only nine devices were understood by more than 80 percent of the respondents. The devices found problematic to teenage drivers include combinations of sign shape and color, warning-symbol signs, white pavement markings, flashing intersection beacons, and circular red/green arrow left-turn-signal displays. Recommendations include revising states’ drivers handbooks and increasing emphasis in the driver education curriculum to clarify the meaning and intent of problematic traffic control devices.

Effect on Vehicle-Pedestrian Conflicts of “Turning Traffic Must Yield to Pedestrians” Sign

1996 ◽  
Vol 1553 (1) ◽  
pp. 38-45 ◽  
Author(s):  
Husham N. Abdulsattar ◽  
Mohammed S. Tarawneh ◽  
Patrick T. McCoy ◽  
Stephen D. Kachman
Keyword(s):  
Traffic Control ◽  
Signalized Intersections ◽  
Legal Obligation ◽  
Left Turn ◽  
Right Of Way ◽  
Two Cities ◽  
Before And After ◽  
Left And Right ◽  
Control Devices ◽  
The Right

Left- and right-turn movements at signalized intersections have been found to be three to six times more hazardous to pedestrians than through movements mainly because drivers fail to observe or yield the right of way to pedestrians. The objective was to evaluate the Turning Traffic Must Yield to Pedestrians sign, which was aimed at reminding turning motorists of their legal obligation to yield the right of way to pedestrians and, consequently, reducing vehicle-pedestrian conflicts. The sign was installed at 12 marked crosswalks in two cities, and vehicle-pedestrian conflict data were collected before and after its installation. The sign was effective in reducing left-turn conflicts 20 to 65 percent and right-turn conflicts 15 to 30 percent; both reductions were statistically significant at the 0.05 level. The sign was significantly more effective in reducing left-turn conflicts than it was for right-turn conflicts. Percentage conflicts between pedestrians and turning traffic decreased as the pedestrian group size increased. In other words, larger pedestrian group sizes encountered fewer conflicts with turning traffic. This result is true for both left- and right-turn movements, regardless of the presence of the sign. Based on the results of this study, it was recommended that the “Turning Traffic Must Yield to Pedestrians” sign be considered for inclusion in the Manual on Uniform Traffic Control Devices.

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