Study of Driver Behavior at Different PPLT Operations

The implementation of a protected/permitted operation for left-turn movement increases safety at an intersection along with improving operational efficiency and reducing traffic delay. There are mainly five different types of PPLT operations used in different states of the United States. They include Circular Green (CG), Flashing Circular Red (FCR), Flashing Circular Yellow (FCY), Flashing Red Arrow (FRA) and Flashing Yellow Arrow (FYA).  It is important to study drivers’ level of perception for each left turn operation to understand advantages and disadvantages of implementation of Protected-Permitted Left Turn (PPLT) signal phasing.The main objective of this paper is to use a real-time driving simulator to study driver behavior at different left-turn operational scenarios. Design of experiments with different control variables such as traffic volume, time of day, speed limit etc., were determined and the proposed scenarios were implemented in the driving simulator. Results were collected and driver safety was analyzed under all scenarios with respect to the parameter "Time to Collision" (TTC). Statistical analysis was performed using the JMP Statistical tool to determine the change in TTC in each scenario. Response surfaces and Prediction Profilers from JMP were analyzed to determine the best suited PPLT operation under different control variables. Graphs were plotted from the results to propose guidelines for different situations. From the results, it was observed that, during the day-time, Flashing Circular Yellow and Flashing Yellow Arrow are most suitable displays. During the night-time, Flashing Circular Red and Flashing Red Arrow are most suitable.


  • English

Media Info

  • Media Type: Web
  • Features: Figures; References; Tables;
  • Pagination: 17p

Subject/Index Terms

Filing Info

  • Accession Number: 01764359
  • Record Type: Publication
  • Report/Paper Numbers: TRBAM-21-02756
  • Files: TRIS, TRB, ATRI
  • Created Date: Dec 23 2020 11:27AM