A Novel Methodology for Estimating the Capacity and Level of Service for the New Mega Elliptical Roundabout Intersection

Ahmed I Z Mohamed,Yiqiu Tan,Yusheng Ci

doi:10.1155/2020/8467152

Abstract

Mega elliptical roundabout is a new intersection on rural multilane highways. This intersection was developed in a previous paper using simulation data, and the authors found that it is better than interchange (full cloverleaf) in most scenarios of traffic flow. Basically, there are no guidelines or procedures for designing mega elliptical roundabout in AASHTO Green Book, Federal Highway Administration guides, and Highway Capacity Manual. Thus, the purpose of this study is to analyze the traffic operation performance and propose a methodology for calculating the capacity of mega elliptical roundabout and also the level of service by gap acceptance theory. Moreover, this research studied the influence of different values of truck ratios and also different values of a major highway speed on geometric design and traffic operation performance for mega elliptical roundabout. To validate the thoroughness of the proposed methodology, VISSIM simulations were conducted. This research will assist practitioners in determining the appropriate geometric design, assessing mega elliptical roundabout intersections, and making comparisons with other alternatives.

Highlights

E remainder of this research is organized as follows
Its form is an elongated ellipse combining the best functions of the roundabout and the unconventional median U-turn (UMUT) intersection [5]. erefore, the first efforts for this work looked at the studies related to estimating the capacity and level of service for roundabout, conventional median U-turn (MUT) intersection, and UMUT intersection to determine the ideal methodology to estimate the capacity and level of service for mega elliptical roundabout intersection
This paper proposed a methodology for estimating the capacity and level of service for mega elliptical roundabout intersections by gap acceptance theory

Summary

Introduction

E remainder of this research is organized as follows. Section 2 introduces the literature review. Erefore, the first efforts for this work looked at the studies related to estimating the capacity and level of service for roundabout, conventional median U-turn (MUT) intersection, and UMUT intersection to determine the ideal methodology to estimate the capacity and level of service for mega elliptical roundabout intersection. Ey found that due to their limitations, each of these methodologies on its own cannot completely explain the complex behavioural and physical processes involved in roundabout entries; all the models require strong semiempirical or fully empirical bases using data obtained from their countries of origin. Wang and Yang [51] proposed a method to estimate the capacity of the roundabout by modeling weaving gap acceptance at the weaving sections, but they did not calibrate their method

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