Determining the Region of Influence of a Signalized Traffic Intersection by Analysis of Heavy-duty Diesel Vehicle Fuel Consumption

Knowledge of the fuel impacts of traffic control signals, particularly traffic lights, is important for assessing benefits of coordinated control of connected and/or autonomous Vehicles (CAVs) with traffic elements, and for determining sites best suited for smart infrastructure deployments based on environmental impacts. The objective of this work is to determine the region over which knowledge of traffic light information is useful in informing fuel-efficient decisions. This includes the region before a traffic light in where a preview-based controller benefits from planning for the upcoming traffic light, and the region after a light where the vehicle returns to free-flow behavior after coming to a complete stop. In this paper, we collectively refer to these regions as the traffic light's Region Of Influence (ROI). In particular, this work identifies the start and end position of the ROI for a signalized intersection based on simulations and in-vehicle experiments using a heavy-duty diesel truck. To evaluate the fuel consumption of the vehicle accurately, this work uses a gravimetric fuel measurement method to calibrate on-board fuel flow meters for both the inlet and outlet of the fuel tank; the results show agreement within 1% error. Next, this work analyzes the difference in fuel consumption for the heavy-duty vehicle within the ROI, comparing fuel usage of the vehicle traveling through green vs. red traffic lights using simulations of previously published MPC velocity controllers designed to improve fuel usage using traffic light SPaT information. The ROI for MPC-based control was found to be 200m before and 175m after the light. Finally, experimental results are given showing driver, rather than controller, responses that indicate: 1) the human-driven ROI starts approximately 140 m before an intersection and ends approximately 500 m after the intersection; and 2) the heavy-duty diesel vehicle consumes on average 88 grams (34%) less fuel within the ROI when encountering a green light, for each traffic light encounter, compared with encountering a red light.