A Comparative Analysis of Displaced Left-Turn and Four-Leg Signalized Intersections: Operational, Safety, and Environmental Perspectives

Authors

Aishah Elsayed Mohamed, faculty of engineering, menoufia universityFollow
Ibrahim Hashim, Menoufia UniversityFollow
Ahmed Elsayed Hassan, faculty of engineering, Cairo universityFollow

Abstract

Numerous unconventional intersection designs have been suggested as a creative solution to mitigate traffic congestion at heavily crowded at-grade signalized intersections. A lot of these unconventional configurations have demonstrated superior performance compared to conventional intersections regarding average control delay and overall intersection capacity. This study aims to compare the operational, safety, and environmental effectiveness of one such unconventional intersection design known as Displaced Left-turn (DLT). The assessment considers both balanced and unbalanced scenarios in comparison to a conventional intersection (i.e., four-leg signalized intersection). This analysis employs the microscopic simulation software VISSIM along with the Surrogate Safety Assessment Model (SSAM). Operational performance is evaluated based on average vehicle delay, safety performance on simulated conflicts, and environmental performance on CO2 emissions and fuel consumption. Results indicate that the average delays for the DLT were lower than those of the conventional intersection, while the DLT exhibited higher capacity. Moreover, DLT improved safety conditions relative to the conventional intersection and demonstrated clear advantages in terms of fuel consumption and CO2 emissions.

Recommended Citation

Mohamed, Aishah Elsayed; Hashim, Ibrahim; and Hassan, Ahmed Elsayed (2024) "A Comparative Analysis of Displaced Left-Turn and Four-Leg Signalized Intersections: Operational, Safety, and Environmental Perspectives," Journal of Engineering Research: Vol. 8: Iss. 1, Article 24.
Available at: https://digitalcommons.aaru.edu.jo/erjeng/vol8/iss1/24