Method for Evaluating Eco-Driving Behaviors Based on Vehicle Specific Power Distributions

Abstract

Eco-driving is an effective way to reduce vehicle fuel consumption and exhaust emissions. Numerous studies have been conducted on eco-driving, however, there is still a lack of quick and accurate methods for evaluating eco-driving behaviors. This paper proposes a novel method to evaluate eco-driving behaviors based on vehicle specific power (VSP) distributions. First, the baseline speed-specific VSP distributions were derived based on second-by-second vehicle activity data of driving trajectories from 159 drivers on expressways in Beijing. Then, individual drivers’ speed-specific VSP distributions were developed for comparison with the baseline VSP distributions. A model was proposed to evaluate eco-driving behaviors based on the identified differences. Additionally, an eco-driving index (EDI) was designed to quantify the ecological level of driving behaviors for different speed ranges. The consistency of individual driving behaviors across different speed ranges was assessed. The minimum sample size and the appropriate speed bins required for reliable evaluation of individual eco-driving were also determined. The results showed that the differences between individual drivers’ VSP distributions and the baseline distributions could be used to identify eco-driving behaviors, and the eco-driving behaviors of individual drivers were consistent for different speed ranges. The minimum sample size for a reliable evaluation of individual eco-driving behaviors is 420 seconds. Data for speed bins above 70 km/h and below 10 km/h were not representative of the driving behavior and the driving behavior was especially consistent in the speed bins from 20 km/h to 40 km/h.