Arrival time robustness of eco driving strategies under two ATP systems

Author: Jan Hoogenraad
Co-authors: Helen Willeboordse and Rob Goverde
Day: Aspect Day Two
Session: Performance

Under ECO driving, the train driver will aim to arrive exactly on time. In order to ensure this the entry signal needs to clear in time. This paper investigates the robustness of the arrival time with respect to the clearing time of the entry signal, for four train driving strategies. We have chosen a specific situation, and applied two types of ATP systems: the Dutch NS'54 ATB system and ERTMS Level 2. We present detailed calculations of the sequence of actions the driver needs to take in each of these scenarios. Based on these actions, we determine the time of arrival and driver workload. We find that under the Dutch NS'54 ATB system trains arrive tens of seconds late, even if the signal is cleared within the timetable headway. If the signal clears later than the timetable headway, several driving strategies yield delays up to 60 seconds under the Dutch NS'54 ATB system. We compare the NS'54 ATB results ERTMS Level 2, using the same End-of-Authority (EoA) and speed restrictions (SRs). We use the same block lengths (rather than shorter blocks that could be used to optimize for either ATP system) in order to make a fair (apple to- apple) comparison. We show that in ECO driving under ERTMS Level 2, trains will experience little delay, even if the timetable headway is not met. We show that ERTMS Level 2 in combination with ECO driving improves robustness compared to the Dutch NS'54 ATB system against a later clearing of the entry signal. Also workload is reduced under ERTMS Level 2. This improved robustness and lower workload comes on top of the shorter running times and shorter headways that are inherently present for ERTMS Level 2 in the situation studied.