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ERTMS Bridging the gap between technology and
adoption: a Human Factors case study
Elaine Thompson, Mott MacDonald
Introduction
• Considerations of introducing European Rail Traffic
Management System (ERTMS) / European Train Control
System (ETCS) on UK network
• Retrofit to existing trains and implementation in new build
• Highlighted the key factors that needed to be considered
for adoption
Challenges
•
ERTMS/ETCS Driver Machine Interface options for
future train cab design
•
Requires the transition between European Train Control
System (ETCS) and existing train cab systems (Class B)
on routes
•
Management of these interfaces in terms of cab fitment
and driver support is a key issue
System Integration Challenges
System
Reliability
Train
protection &
safety
Position &
reach
ETCS DMI
and Class
B
integration
Cab
environment
Display
technology
Aims of the study
•
Three main issues relating to the fitment of ETCS Driver
Machine Interface (DMI) in rolling stock;
– Design and level of integration of existing Class B
systems within the train cab with the DMI
– Appropriate technology for the DMI screen that
optimises the train cab environment and train driver
performance
– Choice of DMI interface - touch screen or soft key
Approach
• 3 levels of integration considered:
– No Integration: AWS and TPWS indications and controls
separate to the ETCS DMI
– Partial Integration: Speedometer, AWS and TPWS
indications integrated, AWS acknowledge button separate
– Full Integration: Automatic Warning System (AWS) and
Train Protection Warning System (TPWS) indications and
controls, and speedometer fully integrated within the
ETCS DMI.
Existing Cab Layout (Class 43)
Existing
Class 43
Non-Integrated Solution
Class 43
Fully Integrated Solution
Class 43
Transition between ETCS and AWS/TPWS
AWS/
TPWS
ETCS
AWS/
TPWS
Transition between ETCS and AWS/TPWS
• Factors to reduce potential for errors
– Provide clear visual indication of the engaged level of
train protection
– Ensure adequate visibility of controls and indications
in all lighting conditions
– Provide good feedback to the driver to confirm that
control inputs have been successful
AWS/TPWS integration
• Partially integrated solution appears to offer most benefit
– AWS acknowledge button separate
– Consider ETCS acknowledge button also separate
• Cab fitment
– Reduced clutter on the driver console
• Impact on performance
– Reduced visual clutter in the cab means that attention
is focussed on the DMI, which provides visual
confirmation of train control
DMI Interface – Touch Screen vs. Soft Keys
• Touch screen:
+ More flexible layout of
information
+ Only ‘active buttons’
displayed, can reduce
workload
- Likely to have higher
reflectance value
Image Source: ERA_ERTMS_015560 ETCS Driver Machine
Interface
DMI Interface – Touch Screen vs. Soft Keys
• Soft Keys:
+ Lower screen
reflectance value
+ Increased tactile
feedback
- Larger DMI unit, less
flexible layout
Integrated display of AWS/TPWS
• Design of AWS/TPWS interface, considerations:
– Most recent ERA DMI standard allows more flexibility
on screen design
– ‘Customisable’ or ‘Unified’ layout options
– Design of indications – retain AWS ‘sunflower’ or
design a new indication
– Interaction with AWS acknowledge button –
frequency of use
Latest developments for GB standards
• Work to update standards:
– GK/RT8075 – AWS and TPWS Interface Requirements
• Cover touch screen and soft key options
– GK/RT0036 – Transitions between Signalling Systems
• Number and frequency of transitions
• Driver workload around transitions
• Understanding fully the impact and potential errors
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