Aggressive-dynamics metrics for drive-cycle characterization

Abstract

In the pursuit of policies and regulations on real-world driving emissions, it becomes necessary to quantifiably define what constitutes “real-world driving.” Measurements of ambient temperature, pressure, and humidity can be used to quantify the weather. Routes can be quantified by their fixed characteristics such as length, road grades, and speed limits. Variable traffic conditions can be quantified by the number of traffic encounters, the number of traffic stops, the fraction of traffic limited driving, et cetera. A real-world drive cycle arises from the interactions between the driver, weather, route, and traffic. People sometimes colloquially described drive cycles in terms of aggressiveness. This subjective characteristic of aggressiveness is here quantified using dynamics metrics, and it is discussed how such metrics could be used by researchers and regulators. A new dynamics metric, the average judicative element, is presented in this investigation. This new metric is compared to previously developed metrics, and its advantages and disadvantages are considered. It is argued how the average judicative element is a superior aggressive-dynamics metric for characterizing drive cycles in scientific studies and governmental regulations.