Eco-driving is an environmentally friendly driving manner which improves fuel economy. Since Eco-driving has an immediate and significant effect on improving vehicle's fuel economy, introduction of devices, that main functions are measuring vehicle speed and elapsed time on-board, making alerts when drivers deteriorate fuel economy, and recording driving patterns, is being promoted to support Eco-driving. However, fuel economy improvement rates by Eco-driving show uneven distribution because many factors such as the weather, road and traffic conditions, types of vehicles and drivers' individualities have influence on fuel economy.
In this research, correlations between fuel economy improvement and drivers' individualities were examined on a proving ground. Then, in order to estimate the effect of fuel economy by Eco-driving in real traffic conditions, test drives using more than 1,000 trucks were carried out for 5 months with compared to the data of no Eco-driving. As a result, correlations between types of running patterns and fuel economy improvement were clarified.