Melcher Zeilstra
INTERGO human factors & ergonomics
Melcher Zeilstra is a certified human factors consultant (European Ergonomist) and partner at Intergo. He is president of the Foundation of Certification of Dutch European Ergonomists. Intergo a consultancy in human factors and ergonomics, with roots in Dutch Railways. Besides rail industry, Intergo is working for clients in transportation (public transport, aviation, traffic management, waterways), process industry and energy, and health care. Melcher holds a strong focus on safety, human reliability and workload. But also system performance and introduction of innovations into operation are important drivers in his consultancy work.
In 2014 the Ministry of Transport decided for implementation of ERTMS (European Railway Traffic Management System) on the main corridors in Holland. Prior to formulating a concrete strategy a pilot with ERTMS in commercial train service was performed on the track between the cities of Amsterdam and Utrecht. In total about 124.000 km and 7500 journeys were driven with ERTMS Level 2.
The pilot was evaluated with 142 research items, among which 20 related to human factors. The research was aimed at train drivers, train dispatchers and operational management.
This paper will focus on the effects of ERTMS on workload and human error of the train driver by comparing driving with conventional (ATB only), Dual Signalling and ERTMS L2-only train protection. Typical research questions were:
- What are differences in driver’s workload and situation awareness?
- Does the driver use the planning area and how does this influence his driving behaviour?
- Does ERTMS experience influence driving on conventional tracks?
A simulator experiment was conducted. 60 train drivers participated in the experiment and each train driver performed 8 runs. Driving performance was monitored, eye tracking data was collected during the runs and after each run the train drivers filled out a questionnaire. Day to day experience during service was collected through workshops and surveys. Also, data from the infrastructure was collected.
Results show that during the simulation mental workload with ERTMS L2-only is slightly higher than with conventional or Dual signalling train protection, which may be explained by the relatively inexperience with ERTMS amongst the participants. The survey reveals a higher workload for conventional signalling; most drivers refer to driving in degraded sight conditions. From the workshop it appears that drivers will have the highest workload when handling a malfunction in ERTMS L2-only. In this situation there is no fall-back to conventional train protection.
The simulator experiment showed that the probability of a human error is equal for the three conditions. Situation awareness is high in all of them. Handling malfunctions will cause more errors in Dual Signalling compared to ERTMS-only. Even in ERTMS-only, experience will be a major cause for differences.
Research into the habituation of the train driver to a particular train protection system is performed in the simulator experiment, by use of a questionnaire for train drivers in commercial train service during the pilot and in workshops, and by the use of data about train speeds during commercial service of the pilot.
Most train drivers, in commercial service as well as in the simulator experiment, report that they are always aware which train protection system is active at that moment. According to drivers there are sufficient indications in the cabin and near the track, which point out which train protection system is active at that moment. Nevertheless, 10-18% of all train drivers report that during a short period of time it is possible to make a mistake in this awareness.
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We’d like this paper to be considered for inclusion in the special edition of Applied Ergonomics.
Train control systems including ERTMS, class B systems, GSM-R and Automatic Train Operatio , Human error and human reliability
