## 5 Case Study  
### Operational Benefits  
We collected the driving data from real-time vehicle operations. On the basis of the statistics, the average daily power consumption efficiency of the vehicle was 0.67 km/kWh. The average daily \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Rule** & **IF** & **THEN** & **ROUTE** & **GINI** & **Sample** & **Confidence** \\ \hline
1 & Motor speed & \textless{}425.5 & & L & 0.17 & 359,948 & 326,286 & 90.65\% \\ \hline
2 & Motor speed & \textgreater{}425.5 & & & & & \\ Total voltage & \textgreater{}549.25 & & Low energy & RRL & 0.475 & 73,122 & 48,343 & 66.11\% \\  & Acceleration & \textless{}0.15 & & & & & \\ \hline
3 & Motor speed & \textgreater{}425.5 & & & & & \\ Total voltage & \textgreater{}560.15 & & & & & & \\ Acceleration & \textgreater{}0.15 & & & & & & \\ Average voltage & \textgreater{}3.333 & & & & & & \\ \hline
4 & Motor speed & \textless{}425.5 & & & & & \\ Total voltage & \textless{}549.25 & & & & & & \\ Total current & \textless{}103.65 & & & & & & \\ Acceleration & \textless{}0.85 & & & & & & \\ \hline
6 & Motor speed & \textgreater{}425.5 & & & & & \\ Total voltage & \textless{}549.25 & & & & & & \\ Acceleration & \textgreater{}0.15 & & & & & & \\ Average voltage & \textless{}3.333 & & & & & & \\ \hline
7 & Motor speed & \textgreater{}779.5 & & & & & \\ Total voltage & \textless{}549.25 & & & & & & \\ Total current & \textgreater{}103.65 & & & & & & \\ \hline
8 & Motor speed & \textgreater{}779.5 & & & & & \\ Total voltage & \textless{}549.25 & & & & & & \\ Total current & \textless{}103.65 & & & & & & \\ Acceleration & \textgreater{}0.85 & & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Classification rules of the optimal decision tree model. energy efficiency of this vehicle at medium power consumption was 0.73 km/kWh. It can be seen that the power consumption efficiency of this vehicle falls in the high energy consumption band. Eco-driving, as defined in this study, falls in the medium energy consumption band, thereby effectively improving the power consumption efficiency and operational benefits. This section provides operating data statistics such as the monthly mileage, driving energy consumption, and power consumption efficiency, as shown in Table 8. We can see from the indicators for evaluating the operational benefits that longer mileages or higher power consumption efficiencies help to save energy and reduce carbon emissions as well as driving costs. The three evaluation indicators were power consumption, carbon emission, and driving cost. The formal definitions of carbon emissions and driving cost are given as follows:  
**Definition 3**. : _Carbon Emission The carbon emission refers to total carbon-containing gases emissions caused by the electronic buses. In this study, carbon emission is measured in units of kilogram (kg). The formulation of carbon emission is given by Equation (2) as follows:_  
\[\text{Carbon emission }(kg)=\frac{\text{Mileage }(km)\times\text{Carbon emission factor }(kg/kWh)}{\text{Power consumption }eft\text{iciency }(km/kWh)} \tag{2}\]  
**Definition 4**. : _Driving Cost The driving cost refers to the financial cost per kilometer caused by the electronic buses. In this study driving cost is measured in units of new Taiwan dollars per kilometer (NTD/km). The formulation of driving cost is given by Equation (3) as follows:_  
\[\text{Driving cost }(NTD/km)=\frac{\text{Electricity price }(NTD/kWh)}{\text{Power consumption }eft\text{iciency }(km/kWh)} \tag{3}\]  
From the operating statistics in Table 8, we note that the monthly mileage was approximately 3955 km, and the average monthly power consumption efficiency was 0.67 km/kWh. The eco-driving standards obtained in this study are expected to improve the power consumption efficiency to 0.73 km/kWh. The correlation coefficients of Taiwan Power Company are as follows: the carbon emission was 0.554 kg/kWh [1] and the average electricity price was 2.6253 NTD/kWh [27].