Impact of Autonomous Vehicles on Roundabout Capacity

Othmane Boualam,Attila Borsos,Viktor Nagy,Csaba Koren

doi:10.3390/su14042203

Othmane Boualam, Attila Borsos + Show 2 more

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https://doi.org/10.3390/su14042203

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Journal: Sustainability	Publication Date: Feb 15, 2022
Citations: 13	License type: CC BY 4.0

Affiliation: Széchenyi István University

Abstract

Studying the impact of AVs on our road infrastructure offers a lot of potential in the transportation domain; one of these issues is how capacity will be affected. This paper presents a contribution to this research area by investigating the impact of AVs on the capacity of single-lane roundabouts using a microsimulation model. For the development of the model, a roundabout situated in Győr (Hungary) was selected and field data on the roundabout geometric characteristics as well as traffic volumes were used. Simulations using Vissim were run for various scenarios based on varying input traffic volumes and market penetration rates of AVs to assess queue lengths. The highway capacity manual (HCM) roundabout model was used to estimate the capacity of the existing roundabout. Values of follow-up times and critical gaps were set to decreasing as the penetration rate of AVs increases. The results demonstrated that 20% and 40% AVs in the flow would increase leg capacities by about 10% and 20%, respectively. Furthermore, a reduction in excessive queue lengths was estimated and capacities and queue lengths were calculated by legs. It was found that these are highly influenced by the distribution of flows among legs, and the share of flows in various directions.

Highlights

IntroductionAutonomous vehicles (AVs) will have many fundamental impacts on transportation, creating new challenges for transport and network operators
The circulating flows obtained for each scenario with increasing traffic flow percentages were used to estimate the roundabout capacity for each entry using the highway capacity manual (HCM)
Average queue lengths were taken from the Vissim simulation for each leg and for the five traffic volume cases

Summary

Introduction

Autonomous vehicles (AVs) will have many fundamental impacts on transportation, creating new challenges for transport and network operators. As AV technology rapidly advances, the share of AVs is expected to grow and their programmed behavior to evolve. This evolution will require transport operators to study the coexistence of AVs and conventional vehicles and to rethink road infrastructure standards, so they meet future needs and accommodate both types of vehicles [5,6]. Researchers are interested in studying the impacts of AVs on transportation, especially the key road safety and capacity issues when AVs with different settings are mixed in traffic

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