Comparing a DAS guided driving strategy with a shortest time driving strategy one gets the theoretical saving potential. For typical time buffers and running patterns, it lies over 20 % in main line operation.

The real saving potential is however considerably lower, for three reasons:

• Even without DAS drivers do not pursue a shortest time driving strategy, but use a more energy efficient driving style according to their experience, skill and motivation. If there are no delays this may cut energy consumption by 20%.
• Due to delays the DAS often cannot be used. This may well be the case for about 50% of the trips.
• Purely advisory character of the system: Some drivers may ignore the advice.

Taking these factors into account, the remaining potential in main line transport lies between 5 and 10%. In individual favourable situations this value can even reach 15%.

ESF test runs at DB AG

Simulations and test runs with ESF on the ICE at DB AG yielded the following results:

• The theoretical saving potential is 21,2 %.
• Taking into account that drivers exploit some of this potential without a DAS, the remaining potential is 14,9%.
• If train delays are also taken into consideration, the average savings are about 7,5 %.

Economymeter test runs at NS Reizigers

In-service testing during two years in the Netherlands has yielded an overall reduction of 6 – 7 %. The reason for this value which is much lower than the theoretical potential are delayed trains and drivers ignoring the driving recommendations.