A Survey of Route Bus Speed Change Pattern for Clarifying Electrification Benefits

This study aims to describe the advantages of electrifying regular-route buses. The results of a survey on the speed profile of buses operating on actual routes are presented here. Firstly, we focus on the acceleration / deceleration at the starting / stopping stops specifically for regular-route buses and obtain the following information: I. Starting acceleration from a bus stop is particularly strong in the second half of the acceleration process, being suitable for motor-driven vehicles. II. The features of the stopping deceleration at a bus stop are “high intensity” and “low dispersion,” with the latter enabling the refinement of regenerative settings and significantly lowering electricity economy during electrification. And we compare the speed profile of a fuel cell bus with those of a diesel bus and obtain the following information: III. Motor-driven vehicles have “high acceleration performance” and “no gear shifting” which facilitate the high-intensity stop–start acceleration operation unique to regular-route buses. By calculating and analyzing the jerk amount, we could quantitatively demonstrate the comfortable driving experience while riding on this type of bus where there is no shock due to gear shifting. IV. While the “high acceleration performance” of motor-driven vehicles produces “individual differences in the speed change patterns,” this does not translate to “individual differences in electricity consumption” owing to the characteristics of this type of vehicle. With engine-driven vehicles, measures, such as “slow acceleration” and ”shift up early” are strongly encouraged to realize eco-driving, and any driving style that deviates from these measures is avoided. However, with motor-driven vehicles, the driver does not need to be too concerned about the speed change patterns during acceleration. This characteristic also suggests a benefit in terms of the electrification of buses.