Assessing the Impact of Unconventioanal Median U-turn on Urban Arterial Road

Abstract

Abstract Traffic congestion at signalized intersections is a recurring problem, especially on urban arterials during peak hours. To mitigate congestion, many signalized intersections, in developing countries like Pakistan, are being converted into U-turn, known as Unconventional Median U-turn (UMUT). This research aims to assess the effectiveness of this low-cost "indirect right turn" technique. The performance of the UMUT design was analyzed through various scenarios based on different traffic demands, percentages of right-turn traffic, and median U-turn offsets. Notably, this study focuses solely on the operational analysis of passenger cars, excluding bikes, and heavy vehicles. Additionally, it is limited to minor arterial urban and suburban roads, with no consideration for the U-turn movement on multilane highways. VISSIM, a traffic simulation software, was utilized to simulate intersections, and Python was employed as a programming language via the API (Application Programming Interface) COM interface to generate different UMUT scenarios in VISSIM. The evaluation parameters included average vehicular delay and vehicle travel time. MATLAB was used to develop vehicular delay equations and travel time models for all movements in the UMUT design. These models were based on simulation traffic data obtained from VISSIM. Generalized Linear Models (GLMs) with exponential relationships were used to accurately capture the associations between different input variables and output parameters. These models underwent internal validation procedures to ensure their reliability.