Authors:
Hao Chen
and
Hesham Ahmed Rakha
Affiliation:
Charles E. Via, Jr. Department of Civil and Environmental Engineering, Virginia Tech Transportation Institute, Virginia Polytechnic Institute and State University, 3500 Transportation Research Plaza, Blacksburg, VA 24061, U.S.A.
Keyword(s):
Integrated Controller, Signal Time Optimization, Vehicle Speed Control, Signalized Intersections, Energy-Optimized Solution, Connected, Automated Vehicles, Microscopic Traffic Simulation.
Abstract:
This research develops a bi-level optimizer that provides energy-optimal control for vehicles and traffic signals. The first level optimizes the traffic signal timings to minimize the total energy consumption of approaching vehicles. The traffic signal optimization can be easily implemented in real-time traffic signal controllers and overcomes the shortcomings of the traditional Webster method, which overestimates the cycle length when the traffic volume-to-capacity ratio exceeds 50 percent. The lower-level optimizer is the vehicle speed controller, which calculates the optimal vehicle brake and throttle levels to minimize the energy consumption of individual vehicles. The proposed integrated controller is first tested on an isolated signalized intersection, and then on an arterial network with multiple signalized intersections to investigate the performance of the proposed controller under various traffic demand levels. The test results demonstrate that the proposed integrated contr
oller can greatly improve energy efficiency producing fuel savings of up to 17.7%. It can also enhance traffic mobility by reducing traffic delays by up to a 47.2% and reducing vehicle stops by up to 24.8%.
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