The Multi-Station Based Variable Speed Limit Model for Realization on Urban Highway

Dongmahn Seo,Soobin Jeon,Chongmyung Park

doi:10.3390/electronics9050801

Dongmahn Seo, Soobin Jeon + Show 1 more

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https://doi.org/10.3390/electronics9050801

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Abstract

Intelligent transport systems (ITS) are a convergence of information technology and transportation systems as seen in the variable speed limit (VSL) system. Since the VSL system controls the speed limit according to the traffic conditions, it can improve the safety and efficiency of a transport network. Many researchers have studied the real-time VSL (RVSL) algorithm based on real-time traffic information from multiple stations recording traffic data. However, this method can suffer from inaccurate selection of the VSL start station (VSS), incorrect VSL calculations, and is unable to quickly react to the changing traffic conditions. Unstable VSL systems result in more congestion on freeways. In this study, an enhanced VSL algorithm (EVSL) is proposed to address the limitations of the existing RVSL algorithm. This selects preliminary VSL start stations (pVSS), which is expected to end congestion using acceleration and allocates final VSSs for each congestion interval using selected pVSS. This controls the vehicles that entered the congestion area based on the selected VSS. We used four metrics to evaluate the performance of the proposed VSL (VSS stability assessment, speed control stability assessment, travel time, and shockwave), which were all enhanced when compared to the standard RVSL algorithm. In addition, the EVSL algorithm showed stable VSL performance, which is critical for road safety.

Highlights

Intelligent transportation systems (ITS) are integrated traffic systems based on the convergence of civil engineering and information technology fields
The variable speed limit (VSL) system controls traffic flow by applying suitable speed limits in the regions suffering from traffic congestion
Since the stations and dynamic message sign (DMS) are in different areas, an accurate VSL value cannot be displayed on each DMS device

Summary

Introduction

Intelligent transportation systems (ITS) are integrated traffic systems based on the convergence of civil engineering and information technology fields Such systems aim to provide a low cost/high efficiency traffic management system that enhances traffic safety. Several studies have been performed with the aim of reducing traffic congestion and alleviating the risk of car accidents on urban expressways Both variable speed limit (VSL) and ramp metering technologies are representative methods for improving traffic conditions on expressways [1]. In the VSL system, speed indicators are installed on the roads at regular intervals and the system collects traffic information in real time Based on this information, the VSL system controls traffic flow by applying suitable speed limits in the regions suffering from traffic congestion. Since the VSL system enhances road safety, it is an important solution for upcoming ITS [2,3]

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