Intersection Safety at High-Speed Signalized Intersections: Number of Vehicles in Dilemma Zone as Potential Measure

2004 ◽  
Vol 1897 (1) ◽  
pp. 126-133 ◽  
Author(s):  
Karl Zimmerman ◽  
James A. Bonneson
Keyword(s):  
High Speed ◽  
Signalized Intersections ◽  
Dilemma Zone ◽  
Intersection Safety ◽  
Potential Measure

Determination and Utilization of Dilemma Zone Length and Location for Safety Assessment of Rural High-Speed Signalized Intersections

2020 ◽  
Vol 2674 (4) ◽  
pp. 272-280
Author(s):  
Min-Wook Kang ◽  
Moynur Rahman ◽  
Joyoung Lee
Keyword(s):  
High Speed ◽  
Red Light ◽  
Signalized Intersections ◽  
Percentage Error ◽  
Traffic Operations ◽  
Safety Level ◽  
Zone Length ◽  
Dilemma Zone ◽  
Intersection Safety ◽  
Traffic Conflicts

The objective of the present study is to see how the dilemma zone length and location are related to intersection safety at rural high-speed signalized intersections. For that, dilemma zones at 30 rural signalized intersection approaches where similar traffic operations and land-use conditions are present were identified, and traffic conflicts associated with the dilemma zones were investigated. Drivers’ stop or go behaviors as well as vehicle dynamics (e.g., vehicle speeds and locations) during the yellow and red clearance intervals were collected and analyzed to determine the dilemma zone length and location of each site. Red-light running violations and vehicles’ abrupt stops were also collected to investigate the relationship between such conflicts and dilemma zone length and location. As a result, two dilemma zone conflict models were developed. The analysis results show that the conflict models are accurate enough to predict the safety level of high-speed signalized intersections using the two dilemma zone variables. Results show that the chance of intersection angle conflicts increases if the dilemma zone is located farther from the intersection stop bar. Results also show that there would be a high chance of rear-end conflicts if the dilemma zone length is longer. The models were validated with additional datasets, and acceptable root means square error and mean absolute percentage error values were obtained as a result.

Performance of Advance Warning for End of Green System for High-Speed Signalized Intersections

2005 ◽  
Vol 1925 (1) ◽  
pp. 176-184 ◽  
Author(s):  
Srinivasa R. Sunkari ◽  
Carroll J. Messer ◽  
Hassan Charara
Keyword(s):  
High Speed ◽  
Red Light ◽  
Signalized Intersections ◽  
Traffic Signal ◽  
Traffic Operations ◽  
Dilemma Zone ◽  
Green Approach ◽  
High Speeds ◽  
Approach Speed ◽  
Green System

A major difficulty with traffic signal operation on high-speed approaches is the dilemma faced by approaching motorists when the downstream signal turns yellow. Should the motorists stop or proceed through the intersection? Crashes that may occur at these intersections result in excessive property damage and personal injury because of the high speeds involved. The Texas Transportation Institute has developed a new system named the Advance Warning for End of Green System (AWEGS) for application at high-speed signalized intersections. Typically, dilemma zone detection strategy is based on a certain approach speed (typically the 85th percentile). AWEGS provides protection for the majority of motorists who are not covered by the dilemma zone treatment. AWEGS provides advance warning to motorists by using signs mounted on the roadside. These signs (Be Prepared To Stop When Flashing) would flash a beacon about 5 to 6 s before the onset of the yellow signal for high-speed approaches. Similar systems have been implemented in Canada and in a few U.S. states that use the trailing-green approach, which results in loss of dilemma zone protection every cycle. AWEGS, however, is almost completely independent of the traffic signal controller, and hence the signal controller would continue to provide the dilemma zone protection for which it was designed. The system was implemented at two sites in Waco and Brenham, Texas. Results of AWEGS implementation illustrated an improvement in traffic operations. AWEGS consistently enhanced the dilemma zone protection at intersections and reduced red light running by about 40%.

Fuzzy sets to describe driver behavior in the dilemma zone of high-speed signalized intersections

2012 ◽  
Vol 15 (2) ◽  
pp. 132-143 ◽  
Author(s):  
David S. Hurwitz ◽  
Haizhong Wang ◽  
Michael A. Knodler ◽  
Daiheng Ni ◽  
Derek Moore
Keyword(s):  
Fuzzy Sets ◽  
High Speed ◽  
Driver Behavior ◽  
Signalized Intersections ◽  
Dilemma Zone

Improved Detection and Control System for Isolated High-Speed Signalized Intersections

2003 ◽  
Vol 1856 (1) ◽  
pp. 212-219 ◽  
Author(s):  
Karl Zimmerman ◽  
James A. Bonneson ◽  
Dan Middleton ◽  
Montasir M. Abbas
Keyword(s):  
High Speed ◽  
Control Algorithm ◽  
Signalized Intersections ◽  
Flow Rates ◽  
New Approach ◽  
Dilemma Zone ◽  
Allocation System ◽  
And Control ◽  
Intersection Control ◽  
New System

High-speed signalized intersections have both safety and efficiency problems. The safety problems traditionally have been overcome by using advance detectors. However, at relatively moderate flow rates, multiple advance detector systems tend to extend the green phase to its maximum allowable duration (i.e., max-out). At max-out, drivers on the intersection approach may be faced with the decision to proceed or stop. This creates the safety problem the system was intended to prevent. Also, extending phases to their maximums increases delays to other movements. A new approach to high-speed intersection control is outlined—a dynamic dilemma zone allocation system that uses measured vehicle speeds with a control algorithm to decide when to end the signal phases. The new system was evaluated by simulation and field installation. In both instances, the new system indicated it could improve safety and maintain efficient operations at high-speed intersections.

scholarly journals Analysis of Driver Decisions at the Onset of Yellow at Signalized Intersections

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Juan Li ◽  
Boyu Jiang ◽  
Chunjiao Dong ◽  
Jue Wang ◽  
Xuan Zhang
Keyword(s):  
High Risk ◽  
Reliability Index ◽  
Latent Class ◽  
Signalized Intersections ◽  
Low Risk ◽  
New Classification ◽  
Intersection Safety ◽  
Dangerous Driving ◽  
Latent Class Logit ◽  
Risk Categories

Drivers’ decisions to either slow and stop or go at the onset of yellow signal impact on intersection safety. This novel study contributes to the new classification scheme for drivers. Two driving style indexes (i.e., the driving reliability index and dangerous driving index) are adopted, along with other known factors to analyze stop/go decision-making. Initially, the driving reliability index is extracted using a Hidden Markov Model (HMM). The dangerous driving index is calculated based on statistics extracted from dangerous driving records. A latent class logit model is then proposed to explore the factors which influence drivers’ decisions. Drivers are classified for analytical purposes into “low-risk” and “high-risk” categories according to driving styles and age. Results indicate that those considering “low-risk” tend to stop, while drivers considering “high-risk” are inclined to pass intersections. Furthermore, distractions from cell phones have different influences on each group of drivers. These findings help to determine driver preferences and may be used to formulate strategies to reduce unsafe driving occurring at signalized intersections.

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