Evaluation of Effect of Median U-Turns on Multilane Primary Highway Capacity in Thailand through Traffic Micro-Simulation Models

Abstract

This article aims to analyze the effect of median U-turns and estimate the capacity of primary highways in Thailand using a traffic micro-simulation model. Six-lane and four-lane primary highways were selected for the study. The base condition results determined that the maximum capacity of a six-lane primary highway was 2,130 passenger cars/hour/lane, while the four-lane primary highway capacity was recorded as 2,194 passenger cars/hour/lane. Both results were slightly higher than those of the HCM2010 approach. Under prevailing conditions, both sections exhibited lower capacities than the HCM results by approximately 33.7% and 19.8% for the six-lane and fourlane primary highways, respectively, causing the impact of the median U-turn and highway characteristics in Thailand to directly affect traffic and driving behavior. Using the micro-simulation results, an equation was also regressed for estimating the capacity resulting from the impact of the median U-turns and heavy vehicles. These results may be used as guidelines for the design and analysis of multilane highways in Thailand.

The Feasibility and Operational Performance of Implementation Median U-turn Intersections: A CRITIC Method

“…The AHP technique has been used extensively to solve practically all forms of transportation issues. Chaipanha et al (2018) conducted a study to evaluate the effect of median U-turns on multilane primary highway capacity in Thailand. Their research focused on using traffic micro-simulation models to estimate the impact of median U-turns on driving behavior and highway capacity.…”

“…Their research focused on using traffic micro-simulation models to estimate the impact of median U-turns on driving behavior and highway capacity. This study is particularly relevant as it directly addresses the evaluation of median U-turns on highway capacity, which is a key aspect of the multi-criteria decision-making process in transport engineering (Chaipanha et al, 2018). In addition, Al-Sahili et al ( 2018) investigated and modeled illegal U-turn violations at medians of limited access facilities.…”

Drivers' Tendencies to Engage in Aberrant Driving Behaviors That Violate Traffic Regulations in Kuwait

“…As for the effects of U-turns, Tanwanichkul et al found that vehicles executing U-turns through median U-turn openings impede vehicles in the through traffic lanes, especially when the number of turning vehicles is large. This in turn reduces the capacity of the segment [27]. Similarly, Wu et al found that U-turning vehicles obstruct traffic in the U-turning lane as well as for the adjacent through lanes.…”