Actual energy efficiency potential primarily depends on time buffer (provided by timetable) and driving strategy chosen.

A simulation study made at the National Cheng Kung University in Taiwan compared the energy saving effect of different driving strategies (using the train characteristics of German ICE), namely:

1. Reduction of maximum speed, e.g. running the train with the maximum speed of 280 Km/h instead of 300 Km/h;
2. Reduction of maximum acceleration rate, e.g. running the train with 90% of the maximum acceleration when it is in the state of acceleration;
3. Coasting, e.g. starting the train to the coasting state at the place 50% earlier than its original initial place of deceleration;
4. Saw-tooth coasting, e.g. running the train in the coasting state during a speed range between 300 km/h and 275 km/h

Various stopping services of a main line service were considered. Among other the study yielded the following result:

• For the case of a train stopping at all stations, the effect of the acceleration reduction is smaller than that of reduced maximum speed: Strategy 1 leads to an energy consumption reduced by 11% for a running time increased by 3.9%. Strategy 2 (with 80% acceleration rate) saves 4.7% energy for an increase of running time of 3,5 %. For a train stopping at all stations strategy 1 therefore has a better cost/benefit ratio.
• For an express train stopping only at three stops, coasting (strategy 3) is better than reduced maximum speed as far as cost-benefit ratio is concerned.