scholarly journals Improved Safety and Efficiency of Protected/Permitted Right-Turns in Oregon

2018 ◽  
Author(s):  
David Hurwitz ◽  
◽  
Chris Monsere ◽  
Keyword(s):  
Right Turns

Bases for first-order theories and subtheories

1960 ◽  
Vol 25 (2) ◽  
pp. 97-142 ◽  
Author(s):  
William Craig
Keyword(s):  
Axiom System ◽  
Logical Theory ◽  
Theoretical Terms ◽  
First Order ◽  
Right Turns

The extent to which we can grasp the content of a (non-logical) theory, expressing it economically by means of an axiom system or basis, varies greatly. In this paper we shall investigate what degree of economy, or at least regularity, can be achieved for all recursively axiomatizable first-order theories. A useful approach, also of interest in its own right, turns out to be the study of bases for subtheories, where a subtheory of a given theory consists of those theorems from which certain predicate symbols are absent. These predicate symbols might be thought of as the formal counterparts of the “purely theoretical” terms employed by a science, the theory corresponding to the science itself and the subtheory to its “observational consequences”. Roughly speaking, the types of operations involving such predicate symbols will be reduced to a minimum, so that their syntactical role in deductions will emerge more clearly.

Utilization of Auxiliary Through Lanes at Signalized Intersections with Downstream Lane Reductions

1997 ◽  
Vol 1572 (1) ◽  
pp. 167-173 ◽  
Author(s):  
Jamie W. Hurley
Keyword(s):  
Signalized Intersections ◽  
Stepwise Multiple Regression ◽  
Distribution Data ◽  
Highway Capacity ◽  
Left Turn ◽  
Highway Capacity Manual ◽  
Traffic Characteristics ◽  
Geometric Factors ◽  
Auxiliary Through Lanes ◽  
Right Turns

The capacity of multiple through lanes at signalized intersections depends on the distribution of traffic within these lanes, with equal lane distribution corresponding to maximum capacity. However, traffic characteristics, land use, and geometric factors usually prohibit this from occurring. Although the 1994 update of the Highway Capacity Manual considers the case of continuous through lanes at signalized intersections, the default values provided do not address situations in which lane reduction takes place downstream of the intersection. Lane distribution data obtained in the field can remedy the situation but for existing conditions only. This research employed the concept of captive and choice lane users in modeling lane use for intersection configurations with a single continuous through lane and an “auxiliary” through lane, which is continuous upstream of the intersection but is dropped downstream of it. Stepwise multiple regression was performed on data collected at sites in Tennessee to ascertain those factors significantly affecting auxiliary lane use. These factors were found to be ( a) right turns off the facility at the intersection, ( b) total left turns off the facility downstream of the intersection, ( c) right turns onto the facility in the first 122 m (400 ft) upstream of the intersection, ( d) right turns off the facility in the last 152 m (500 ft) of the auxiliary lane, ( e) downstream auxiliary lane length, and ( f) the existence of left-turn bays or two-way continuous left-turn lanes downstream of the intersection. For the configuration studied, lane distribution data often differed considerably from the default values given in the Highway Capacity Manual.

The Effect of Driving Environments on Simulator Sickness

2007 ◽  
Vol 51 (18) ◽  
pp. 1232-1236 ◽  
Author(s):  
Ronald R. Mourant ◽  
Prasanna Rengarajan ◽  
Daniel Cox ◽  
Yingzi Lin ◽  
Beverly K. Jaeger
Keyword(s):  
Optic Flow ◽  
Substantial Contribution ◽  
Simulator Sickness ◽  
Driving Simulators ◽  
City Environment ◽  
Rate Of Increase ◽  
Left And Right ◽  
The City ◽  
Right Turns

In order to be an effective tool for driver evaluation and education, driving simulators need to be better designed to reduce simulator sickness. This study investigated driving in four environments (country, suburban, city, and curves) using a simulator. When driving on straight roads (city and suburban environments) subjects reported less simulator sickness then driving in the city environment (which included left and right turns) and on curves. A mini-SSQ was used to measure the accumulation of simulator sickness over trials. From trial 1 to trial 5, reported simulator sickness increased linearly. From trial 5 through 8, the rate of increase in simulator sickness decreased. We suggest that the rapid and distorted optic flow experienced while executing turns and driving on curves in driving simulators makes a substantial contribution to simulator sickness.

scholarly journals Track Behavior and Crash Risk Analysis of Passenger Cars on Hairpin Curves of Two-Lane Mountain Roads

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Zhigang Yu ◽  
Ying Chen ◽  
Xiaobo Zhang ◽  
Jin Xu
Keyword(s):  
Crash Risk ◽  
Passenger Cars ◽  
Left Turn ◽  
The Road ◽  
Dangerous Driving ◽  
Road Crash ◽  
Driving Conditions ◽  
The Right ◽  
Cutting Point ◽  
Right Turns

Hairpin curves are often employed in alignment layout and an important feature that identifies dangerous driving conditions for mountain roads. However, driving behaviors at hairpin curves remain ambiguous. Field driving tests were conducted in this study on one two-lane mountain road with 11 hairpin curves. Vehicle-mounted equipment was utilized to collect track and lateral distance between the wheels and the lane markings under naturally driving conditions. Track morphology and patterns, risks, and road crash mechanisms were analyzed. The main findings are as follows. Curve cutting was a typical method for negotiating hairpin curves, was observed for left and right turns, and can be classified into three types based on the location of the cutting point, namely, cutting at curve entry, cutting at curve middle, and cutting at curve exit. Based on the lateral positional relationships between tracks and lane markings, six track patterns are determined for left turns and four track patterns for right turns. When passing a right turn by cutting the curve, a driver occupied the right shoulder of the turn; therefore, there is a risk of colliding with the mountain or the guardrail. When making a left turn into hairpin curves, a driver occupied the right shoulder on curve exit, resulting in running off the road or colliding with the guardrail. More than 70% and 60% of drivers occupied the opposite lane when turning right and turning left, respectively, into a hairpin turn, which led to intertwining between the tracks in the two driving directions and therefore a risk of potential collisions.

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.

Optimal Location of U-Turn Median Openings on Roadways

2003 ◽  
Vol 1847 (1) ◽  
pp. 36-41 ◽  
Author(s):  
Huaguo Zhou ◽  
Peter Hsu ◽  
Jian John Lu ◽  
John E. Wright
Keyword(s):  
Optimal Location ◽  
Traffic Operations ◽  
Average Delay ◽  
Working Model ◽  
Left Turns ◽  
State And Local ◽  
Median Opening ◽  
Transportation Agencies ◽  
Right Turns

Many state and local transportation agencies have considered using U-turns as alternatives to direct left turns from driveways or side streets. Median designs are used that prohibit left turns onto the facility and mid-block U-turn median openings to accommodate diverted left turns from side streets or driveways. The location of these U-turn median openings has a great impact on the operations of U-turns. Traffic operations (weaving and delay) for right turns followed by U-turn movements on urban or suburban multilane roadways were analyzed. A working model was developed to guide the location of U-turn median openings by minimizing the average delay for U-turn movements. A case study demonstrates the operational and safety benefits of optimal U-turn median opening location.

Development of Collision Avoidance System in Right Turn Maneuver Using Vehicle-in-the-Loop Simulation

2015 ◽  
Vol 27 (6) ◽  
pp. 627-635 ◽  
Author(s):  
Pongsathorn Raksincharoensak ◽  
◽  
Yuta Akamatsu ◽  
Keyword(s):  
Collision Avoidance ◽  
Control Algorithm ◽  
System Development ◽  
Speed Control ◽  
Test Drive ◽  
Emergency Braking ◽  
Virtual Test ◽  
Collision Avoidance System ◽  
Right Turns

<div class=""abs_img""><img src=""[disp_template_path]/JRM/abst-image/00270006/04.jpg"" width=""300"" /> Right turn collision avoidance</div>Collisions in Japan between vehicles during right turns account for a high number of other intersection accidents. We present collision avoidance that introduces speed control assistance combined with autonomous emergency braking when vehicles approach and a collision becomes imminent. Our proposal uses on-board sensors such as radar and cameras to handle situations without depending on X2X communication and infrastructure. We also propose a speed control algorithm. A “vehicle-in-the-loop test” involving a virtual test drive for rapid system development verifies the effectiveness of our proposals.

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