Autonomous Vehicle-Intersection Coordination Method in a Connected Vehicle Environment

In response to the need for developing coordinated schemes of autonomous vehicles (AVs) at an intersection. This paper presents a novel coordination method for intersection management in a connected vehicle environment. The road network is divided into three logical sections, namely, buffer area, core area and free driving area. In addition, a buffer-assignment mechanism is developed to cooperatively assign a specific crossing span for an individual AV and guide each AV to adjust its entry time and corresponding speed in the core area. A set-projection algorithm and a three-segment linear speed profile are employed to control the trajectories of the AVs in the buffer area. Furthermore, the assignment failure handling process and the crossing rule for human-driven vehicles are advanced to enhance the practicability and reliability of the buffer-assignment mechanism. The performance of the proposed method is evaluated by simulating various traffic conditions on an actual urban network. The simulation experiments and sensitivity analyses demonstrate that the proposed method can significantly reduce 24.2%-77.1% of travel delays, decrease almost 99% of number of stops and improve the sustainability of the traffic system by saving 22.1%-52% of fuel consumption.

I. Introduction

Autonomous vehicles (AVs) have the potential to eliminate car crashes, alleviate traffic congestion and reduce fuel consumption. Such vehicles will open the door to highly safe, efficient and sustainable transportation systems in the future. In December 2014, Google unveiled its first completed self-driving car prototype, which is fully functional. Notably, Google's self-driving cars have driven more than 700,000 miles on California public roads over the past five years [1]. In addition, other famous manufacturers including Audi, BMW, Mercedes-Benz, Nissan, Tesla and Volvo, have announced their intentions to have commercially viable autonomous driving capabilities in multiple vehicle models by 2020 [2]. What's more, several forward-looking U.S. states, including California, Florida, Nevada, Michigan and Washington D.C., are proceeding with AV-enabling legislation to address the barriers to AV adoption and promotion [3]. Assuming an additional five years for driving the price down and marketing promotion, AVs may be available on the mass market by 2025. AVs are inevitable, and one of the accompanying issues is how to manage navigation for AVs across intersections safely and efficiently in a large-scale AV market penetration environment.