Unraveling inter-driver and intra-driver uncertainty: An eco-driving evaluation and optimization method

Driving behavior exhibits uncertainties both between drivers (inter-driver) and within individual drivers (intra-driver). The proportions and relationships of these variations, especially the boundaries of individual drivers' comfort zones and the operational constraints of manual driving behavior, are not well understood in eco-driving research. This study aims to develop an eco-driving behavior evaluation and optimization model that accounts for individual driving habit constraints. Driver behavior instability was characterized by analyzing the standard deviation of output power. Inter-driver behavioral uncertainty was assessed by analyzing operational data from different drivers, while intra-driver behavioral uncertainty was represented through data from the same driver across various trip conditions. Furthermore, an individualized stepwise optimization eco-driving model (ED-ISOM) for varying driving conditions, incorporating physiological and psychological factors, was developed to provide comprehensive feedback on driver behavior. Findings reveal that, within the speed range of 20–100 km/h, the ratio of intra-driver to inter-driver energy consumption uncertainty ranges from 0.228 to 0.558 and increases with speed. Moreover, drivers classified under the same type may exhibit diverse driving behaviors. A normal-type driver traveling at speeds of 30–35 km/h displays 16.3 % aggressive behavior and 26.6 % cautious behavior. The ED-ISOM reduces fuel consumption by 3.5 %–10.1 %.