Railway Automation, ERTMS and DATO Glossary
This glossary collects the key terms used across Voie Libre articles on railway automation, ERTMS, ETCS, ERTMS/ATO, Traffic Management Systems, Remote Driving and DATO.
It is a living page. It will be updated as new articles are published and as the European railway automation architecture continues to evolve.
Last update: 2026-06
Browse by topic
- Essential concepts
- Automation levels and train operation
- Train protection and ETCS
- Capacity, Hybrid Train Detection and Moving Block
- ERTMS/ATO and automatic driving
- Traffic Management and operational planning
- DATO and system architecture
- Remote Driving
- European framework and programmes
1. Essential concepts
Railway automation
Railway automation refers to the progressive automation of functions involved in train operation, railway supervision, traffic management, degraded-mode handling and operational decision-making. It is not limited to automatic driving: it also includes train protection, traffic management, remote supervision, onboard intelligence, data architecture and responsibility allocation.
Related articles: Railway Grades of Automation, Automatic Train Operation, Railway Automation: From Automatic Driving to Autonomous Operation
See also: GoA, ATP, ATO, DATO, TMS
Interoperability
Interoperability is the ability to allow safe and uninterrupted movement of trains while achieving specified levels of performance. In the European railway context, it requires harmonised technical requirements, harmonised operating rules and compatible onboard and trackside systems.
Related articles: ERTMS, ERTMS/ETCS, ERTMS/ATO
See also: ERTMS, ETCS, TSI CCS, Class B system
Safety envelope
A safety envelope is the set of limits within which train movement is authorised and supervised. It can include speed limits, braking curves, distance to target, Movement Authority, gradients, train properties and signalling constraints. In an automated railway, ATO may drive the train, but the safety envelope remains supervised by the train protection system.
Related articles: Automatic Train Protection, ERTMS/ETCS, ERTMS/ATO
See also: ATP, ETCS, Movement Authority, Braking Curve
System-of-systems
A system-of-systems is an architecture made of several independent systems that must cooperate to deliver a higher-level function. DATO, GoA4, Remote Driving and automated railway operation are system-of-systems topics because they involve rolling stock, ETCS, ATO, TMS, communications, data, supervision, cybersecurity and operational rules.
Related articles: Railway Automation: From Automatic Driving to Autonomous Operation, Remote Driving, A systemic approach to DATO
See also: DATO, GoA4, Responsibility allocation, Remote Supervision Centre
Degraded mode
A degraded mode is an operating situation in which one or more systems, functions or external conditions are no longer nominal. Railway automation must define how trains continue, stop, recover or transfer responsibility when systems such as communication, train integrity, perception, localisation or supervision are degraded.
Related articles: Automatic Train Protection, Railway Automation: From Automatic Driving to Autonomous Operation, Remote Driving
See also: Fallback, Recovery mode, Remote Driving, Safety envelope
Responsibility allocation
Responsibility allocation is the way operational responsibilities are distributed between humans, onboard systems, trackside systems and operational control. It becomes central when moving from GoA2 to GoA4 or from onboard driving to Remote Driving, because tasks historically performed by the driver must be reassigned.
Related articles: Railway Automation: From Automatic Driving to Autonomous Operation, Remote Driving
See also: GoA4, Handover of control, Remote Driver, DATO
2. Automation levels and train operation
Grade of Automation / GoA
A Grade of Automation is an automation level of train operation resulting from the sharing of responsibility for basic train operation functions between operations staff and the system. GoA is used to distinguish different operational realities, from manual driving to unattended train operation.
Related articles: Railway Grades of Automation, Railway Automation: From Automatic Driving to Autonomous Operation
See also: GoA0, GoA1, GoA2, GoA3, GoA4
GoA0
GoA0 corresponds to operation without automatic train protection supervising train movement. The driver drives on sight and controls the train according to the environment, signals, obstacles and operating rules.
Related articles: Railway Grades of Automation
See also: Driving on sight, ATP, GoA1
GoA1
GoA1 corresponds to manual driving supervised by an Automatic Train Protection system. The driver drives the train, while the protection system supervises compliance with speed restrictions, signal aspects or movement limits and may apply braking if necessary.
Related articles: Railway Grades of Automation, Automatic Train Protection
See also: ATP, Safety envelope, Emergency braking
GoA2
GoA2 corresponds to automatic train driving with a driver in the cab. The ATO controls traction and braking, while the train protection system supervises movement and the driver remains responsible for observation, intervention and degraded situations.
Related articles: Railway Grades of Automation, Automatic Train Operation, ERTMS/ATO
See also: ATO, ATP, ERTMS/ATO, Journey Profile
GoA3
GoA3 corresponds to automatic train operation without a driver in the cab, but with staff still present onboard. The onboard staff may support passenger service or intervene in certain degraded situations, but driving is automated.
Related articles: Railway Grades of Automation, Railway Automation: From Automatic Driving to Autonomous Operation
See also: GoA4, Remote supervision, Degraded mode
GoA4
GoA4 corresponds to unattended train operation, where no onboard staff is required for train operation. GoA4 is not simply ATO without a driver: it requires a wider system able to replace or reallocate the responsibilities historically performed in the cab.
Related articles: Railway Grades of Automation, Railway Automation: From Automatic Driving to Autonomous Operation, Remote Driving
See also: DATO, System-of-systems, Remote Driving, Responsibility allocation
Unattended Train Operation / UTO
Unattended Train Operation is an operating mode in which train operation does not require onboard staff. It is usually associated with GoA4 and requires automated driving, supervision, passenger-related procedures, degraded-mode management and remote operational oversight.
Related articles: Railway Grades of Automation, Railway Automation: From Automatic Driving to Autonomous Operation
See also: GoA4, Remote supervision, DATO
Driving on sight
Driving on sight means the driver drives at a speed that allows the train to stop before an obstacle on the track. It relies on the driver’s direct perception of the environment and is different from operation under full train protection supervision.
Related articles: Railway Grades of Automation, Automatic Train Protection
See also: GoA0, ATP, Direct perception
Train Driver
A train driver is a person capable and authorised to drive trains in an autonomous, responsible and safe manner. In railway automation, the driver’s role changes depending on the Grade of Automation and can be partially replaced, supported or moved to a remote location.
Related articles: Railway Grades of Automation, Remote Driving
See also: Remote Driver, GoA2, GoA4
3. Train protection and ETCS
Automatic Train Protection / ATP
Automatic Train Protection is a safety system that enforces compliance with, or observation of, speed restrictions and signal aspects by trains. ATP supervises train movement and may automatically apply braking when the train exceeds authorised limits.
Related articles: Automatic Train Protection, ERTMS/ETCS
See also: ETCS, Safety envelope, Emergency braking
ERTMS
ERTMS stands for European Rail Traffic Management System. It is the European signalling and operation management system encompassing ETCS for control-command, ATO for automatic train operation, and FRMCS and/or GSM-R for voice and data communication.
Related articles: ERTMS, ERTMS/ETCS, ERTMS/ATO
See also: ETCS, ERTMS/ATO, FRMCS, GSM-R
ETCS
ETCS stands for European Train Control System. It is the control-command part of ERTMS and provides a harmonised European train protection system, supervising train movement against authorised speed and distance limits.
Related articles: ERTMS/ETCS, From Fixed Blocks to Moving Block
See also: Movement Authority, EVC, DMI, RBC
ERTMS/ETCS onboard equipment
ERTMS/ETCS onboard equipment is the software and hardware part of the onboard equipment that fulfils the ERTMS/ETCS specification. It supervises train movement, processes trackside information, estimates speed and position, calculates braking curves and interfaces with the driver.
Related articles: ERTMS/ETCS
See also: EVC, DMI, Odometry, BTM
European Vital Computer / EVC
The European Vital Computer is the core computing unit of the ETCS onboard equipment. It processes information from trackside, onboard sensors, train data and driver inputs in order to supervise the train safely.
Related articles: ERTMS/ETCS
See also: ETCS, DMI, Odometry, Movement Authority
Driver Machine Interface / DMI
The Driver Machine Interface is the interface that enables direct communication between the ERTMS/ETCS onboard equipment and the driver. It displays ETCS information such as permitted speed, supervision status, targets and operational messages.
Related articles: ERTMS/ETCS, Automatic Train Protection
See also: EVC, Cab signalling, Driver acknowledgement
Airgap
The airgap is the set of interfaces between track and train. In ERTMS/ETCS, it includes Eurobalise, Euroloop and Euroradio interfaces and is central to technical interoperability.
Related articles: Automatic Train Protection, ERTMS/ETCS
See also: Eurobalise, Euroradio, Track-to-train interface
Application Level
ERTMS/ETCS Application Levels express the possible operating relationships between track and train. They depend on the trackside equipment used, the way trackside information reaches the onboard equipment, and how functions are distributed between trackside and onboard equipment.
Related articles: ERTMS/ETCS
See also: ETCS Level 0, ETCS Level 1, ETCS Level 2, ETCS Level NTC
ETCS Level 0
ETCS Level 0 covers operation where the ETCS onboard equipment is operating in an area without operational ERTMS/ETCS trackside equipment and without an operational national system.
Related articles: ERTMS/ETCS
See also: Application Level, ETCS Level NTC
ETCS Level NTC
ETCS Level NTC is used when ETCS onboard equipment operates under a national train control system, often through a Specific Transmission Module. It is important during migration because national systems remain present on many networks.
Related articles: ERTMS/ETCS, Migration to ERTMS/ATO
See also: Class B system, Legacy signalling, STM
ETCS Level 1
ETCS Level 1 is an ERTMS/ETCS application level overlaid onto conventional lineside signalling. It uses Eurobalises, and possibly Euroloop or radio infill, to transmit Movement Authorities to the train while relying on conventional means to determine train position and integrity.
Related articles: ERTMS/ETCS, Migration to ERTMS/ATO
See also: Eurobalise, LEU, Lineside signalling
ETCS Level 2
ETCS Level 2 is a radio-based train control system that provides full cab signalling and does not require lineside signals, although lineside signals may still be implemented. Movement Authorities are generated trackside and transmitted to the train via Euroradio; train detection and separation can rely on RBC cooperation with the train and/or other trackside equipment.
Related articles: ERTMS/ETCS, From Fixed Blocks to Moving Block
See also: RBC, Euroradio, Cab signalling, Fixed block
Movement Authority / MA
A Movement Authority is the permission given to a train to move up to a defined limit, under specified route, speed and infrastructure conditions. In ETCS, it is generated trackside and supervised onboard.
Related articles: ERTMS/ETCS, From Fixed Blocks to Moving Block
See also: End of Authority, RBC, ETCS Level 2
End of Authority / EoA
The End of Authority is the location to which the train is permitted to proceed and where the target speed is zero. It is a fundamental concept for ETCS supervision.
Related articles: ERTMS/ETCS, From Fixed Blocks to Moving Block
See also: Movement Authority, Danger Point, Braking curve
Braking curve
A braking curve is the prediction of train speed decrease versus distance, calculated from a mathematical model of train braking dynamics and track characteristics ahead. In ETCS, braking curves are used to supervise whether the train can stop before its target.
Related articles: Automatic Train Protection, ERTMS/ETCS
See also: Emergency braking, Service braking, Safety envelope
Emergency braking
Emergency braking is the application of a predefined brake force in the shortest time in order to stop the train with a defined level of brake performance. It can be triggered by the train protection system when the train risks exceeding supervised limits.
Related articles: Automatic Train Protection, ERTMS/ETCS
See also: ATP, Braking curve, Service braking
Eurobalise
A Eurobalise is a balise compliant with the ERTMS/ETCS specification. It is a passive transponder mounted on the track that communicates with a train passing over it and can provide location reference and track-to-train data.
Related articles: ERTMS/ETCS
See also: Balise Group, BTM, ETCS Level 1
Balise Transmission Module / BTM
The Balise Transmission Module is a module inside the ERTMS/ETCS onboard equipment used for intermittent transmission between track and train. It processes uplink signals and retrieves application data telegrams from balises.
Related articles: ERTMS/ETCS
See also: Eurobalise, EVC, Airgap
Lineside Electronic Unit / LEU
A Lineside Electronic Unit is trackside equipment used in ETCS Level 1 to provide variable signalling information to Eurobalises. It connects conventional signalling information to ETCS track-to-train transmission.
Related articles: ERTMS/ETCS, Migration to ERTMS/ATO
See also: ETCS Level 1, Eurobalise, Lineside signalling
Radio Block Centre / RBC
A Radio Block Centre is a trackside ETCS component used in ETCS Level 2 to provide information to ETCS-controlled trains via radio. It knows each ETCS-controlled train individually through the ETCS identity of its leading onboard equipment and transmits Movement Authorities.
Related articles: ERTMS/ETCS, From Fixed Blocks to Moving Block
See also: ETCS Level 2, Euroradio, Movement Authority
Euroradio
Euroradio provides the functions and message protocols required to create an acceptably safe communication channel between ERTMS/ETCS trackside and onboard equipment over an open radio network.
Related articles: ERTMS/ETCS
See also: RBC, ETCS Level 2, GSM-R, FRMCS
GSM-R
GSM-R is the railway version of GSM used for railway voice and data communication. In ERTMS, it has historically served as a radio bearer for ETCS and ATO communication.
Related articles: ERTMS, ERTMS/ETCS
See also: FRMCS, Euroradio, ERTMS
FRMCS
FRMCS stands for Future Railway Mobile Communication System. It is the future railway communication system intended to support voice and data communication for railway applications, including ERTMS/ETCS and ERTMS/ATO.
Related articles: ERTMS, ERTMS/ETCS
See also: GSM-R, Euroradio, ERTMS
Interlocking
Interlocking is the control of the setting and releasing of signals and points to prevent unsafe conditions. In conventional railway signalling, the interlocking remains a core safety system for route setting, point control and prevention of conflicting movements.
Related articles: Automatic Train Protection, ERTMS/ETCS, From Fixed Blocks to Moving Block
See also: Points, Route-centric signalling, RBC
Cab signalling
Cab signalling provides signalling information directly to the driver in the cab rather than relying only on lineside signals. ETCS Level 2 provides full cab signalling and can therefore operate without lineside signals.
Related articles: Automatic Train Protection, ERTMS/ETCS
See also: ETCS Level 2, DMI, Lineside signalling
Lineside signalling
Lineside signalling uses physical signals along the track to convey movement instructions or warnings to the driver. It remains important for conventional operation and for migration concepts such as Lineside Signalling Interpretation.
Related articles: Automatic Train Protection, Migration to ERTMS/ATO
See also: Signal aspect, PER, SCV
Signal
A signal is a visual display device that conveys instructions or advance warning regarding the driver’s authority to proceed. In migration architectures, the signal aspect may be perceived onboard and converted into ETCS-compliant data.
Related articles: Automatic Train Protection, Migration to ERTMS/ATO
See also: Lineside signalling, Signal aspect, PER
Signal aspect
A signal aspect is the visual indication displayed by a signal. In Lineside Signalling Interpretation, the signal aspect is perceived by an onboard perception component and used to generate ETCS-compliant information.
Related articles: Migration to ERTMS/ATO
See also: Lineside signalling, PER, SCV
Class B system
A Class B system is a national legacy train protection or signalling system that exists alongside the European Class A system, ERTMS/ETCS. Class B systems are an important migration issue because they contribute to fragmentation and onboard complexity.
Related articles: ERTMS, ERTMS/ETCS
See also: ETCS Level NTC, Legacy signalling, Interoperability
4. Capacity, Hybrid Train Detection and Moving Block
Block
A block is a method of controlling train separation by dividing the line into sections, normally with no more than one train in each section. A block can be fixed or moving.
Related articles: From Fixed Blocks to Moving Block
See also: Fixed block, Moving Block, Headway
Fixed block
A fixed block is a block whose section limits are at fixed locations. In fixed-block signalling, a train is normally allowed to move into the next block only when the block ahead is clear.
Related articles: ERTMS/ETCS, From Fixed Blocks to Moving Block
See also: Block, Track circuit, Axle counter
Track circuit
A track circuit is a trackside train detection system used to determine whether a section of track is occupied. It is one of the conventional ways to support fixed-block signalling and train separation.
Related articles: Automatic Train Protection, From Fixed Blocks to Moving Block
See also: Trackside Train Detection, Axle counter, Fixed block
Axle counter
An axle counter is a trackside train detection system that counts axles entering and leaving a section to determine whether the section is occupied or clear. It is commonly used as an alternative to track circuits.
Related articles: Automatic Train Protection, From Fixed Blocks to Moving Block
See also: Trackside Train Detection, Track circuit, Fixed block
Trackside Train Detection / TTD
Trackside Train Detection refers to trackside equipment used to determine track occupation, such as track circuits or axle counters. In Hybrid Train Detection, TTD remains present but can be complemented by virtual sections and train-reported information.
Related articles: From Fixed Blocks to Moving Block
See also: Track circuit, Axle counter, HTD, VSS
Hybrid Train Detection / HTD
Hybrid Train Detection is an ETCS-based capacity concept that keeps a physical train detection layer while adding a virtual layer above it. It uses train position reports, train integrity and train length to release infrastructure more finely than physical TTD sections alone.
Related articles: From Fixed Blocks to Moving Block
See also: Hybrid Level 3, VSS, Train integrity, Train length
Hybrid Level 3 / HL3
Hybrid Level 3 is a historical term closely related to Hybrid Train Detection. It refers to an ETCS Level 2/3 migration concept where physical train detection is reduced or complemented by train integrity information and virtual track sections.
Related articles: From Fixed Blocks to Moving Block
See also: HTD, ETCS Level 2, VSS
Virtual Sub-Section / VSS
A Virtual Sub-Section is a smaller virtual section defined inside a physical train detection section. It is not detected directly by trackside equipment; its state is calculated using train position, train length and train integrity information.
Related articles: From Fixed Blocks to Moving Block
See also: HTD, Trackside Train Detection, Train rear end
Moving Block
Moving Block is a signalling principle in which train separation is not primarily governed by fixed block boundaries. Instead, safe separation is calculated dynamically based on train position, train length, safe front and rear ends, braking performance and infrastructure state.
Related articles: From Fixed Blocks to Moving Block
See also: Moving Block System, Train-centric signalling, Safe train separation
Moving Block System / MBS
A Moving Block System is a train-centric signalling architecture that manages train objects, movement permissions, trackside assets and operational state to enable dynamic train separation. It goes beyond simply shortening fixed blocks.
Related articles: From Fixed Blocks to Moving Block, A systemic approach to DATO
See also: Moving Block, Movement Permission, Train-centric signalling
Train-centric signalling
Train-centric signalling is an architecture in which the train becomes a central source of information for safe movement: position, speed, length, integrity and operational state. It contrasts with architectures where track occupation is primarily determined by fixed trackside sections.
Related articles: From Fixed Blocks to Moving Block, Railway Automation: From Automatic Driving to Autonomous Operation
See also: Moving Block, ASTP, Train integrity
Route-centric signalling
Route-centric signalling is an architecture where safe movement is organised mainly around routes set and locked by interlocking, physical track occupation and conventional route logic. ETCS Level 2 can be superimposed on such architectures.
Related articles: ERTMS/ETCS, From Fixed Blocks to Moving Block
See also: Interlocking, RBC, Train-centric signalling
Headway
Headway is the time interval between two trains running on the same infrastructure. It is a key indicator of line capacity and depends on signalling, train separation, braking performance, dwell times, junctions and operational constraints.
Related articles: From Fixed Blocks to Moving Block, Traffic Management System
See also: Safe train separation, Capacity envelope, Moving Block
Safe train separation
Safe train separation is the distance and operational protection required to keep trains from conflicting or colliding. Reducing safe train separation without reducing safety is one of the key objectives of HTD and Moving Block.
Related articles: From Fixed Blocks to Moving Block
See also: Headway, Braking curve, Train rear end
Capacity envelope
The capacity envelope is the theoretical or technical capacity made possible by infrastructure, signalling, rolling stock and operational constraints. HTD and Moving Block can increase the signalling capacity envelope, while ATO and TMS help convert it into usable operational capacity.
Related articles: From Fixed Blocks to Moving Block, ERTMS/ATO, Traffic Management System
See also: Usable capacity, Headway, TMS
Usable capacity
Usable capacity is the part of the theoretical capacity envelope that can actually be used in daily operation. It depends not only on signalling, but also on train performance, driving precision, dwell times, traffic management, degraded modes and operational reliability.
Related articles: From Fixed Blocks to Moving Block, ERTMS/ATO
See also: Capacity envelope, ATO, TMS
Train position report
A train position report is information sent by a train to the trackside system about its position and related status. In ETCS Level 2, HTD and Moving Block, position reports can be used to support track occupation, Movement Authority calculation and train separation.
Related articles: ERTMS/ETCS, From Fixed Blocks to Moving Block
See also: ETCS Level 2, ASTP, Train integrity
Safe train position
Safe train position is a position estimate with safety properties suitable for use by signalling or automated operation. It is central to train-centric architectures because the system relies more heavily on the train’s ability to locate itself.
Related articles: From Fixed Blocks to Moving Block, Railway Automation: From Automatic Driving to Autonomous Operation
See also: ASTP, Odometry, Train position report
Train rear end
The train rear end is the back end of the train. It becomes a capacity-critical concept because track can only be released safely behind a train if the system knows where the train ends and whether it is still complete.
Related articles: From Fixed Blocks to Moving Block
See also: Train length, Train integrity, Safe rear end
Safe rear end
The safe rear end is the rear end of the train known with sufficient safety confidence for signalling use. It is a key input for releasing infrastructure behind a train and reducing safe separation.
Related articles: From Fixed Blocks to Moving Block
See also: Train rear end, Train length, Train integrity
Train integrity
Train integrity indicates whether the train is still complete. If the train cannot confirm its integrity, the signalling system must become more conservative because part of the train may remain on the track behind the reported front position.
Related articles: From Fixed Blocks to Moving Block
See also: Train length, TIMS, DAC
Train length
Train length is the length of the complete train, used to determine the rear end from the train front position. In HTD and Moving Block, train length becomes an operational input for releasing track behind the train.
Related articles: From Fixed Blocks to Moving Block
See also: Train rear end, Train integrity, OTI-L
Train Integrity Monitoring System / TIMS
A Train Integrity Monitoring System is an onboard system intended to determine whether the train is complete. It is especially important for train-centric capacity concepts where track release depends on confirmed train integrity.
Related articles: From Fixed Blocks to Moving Block
See also: Train integrity, Train length, DAC
Advanced Safe Train Positioning / ASTP
Advanced Safe Train Positioning is an onboard safe positioning capability intended to provide more accurate and reliable train position information. It can combine multiple technologies and supports ETCS, ATO, TMS and train-centric capacity concepts.
Related articles: From Fixed Blocks to Moving Block, Railway Automation: From Automatic Driving to Autonomous Operation
See also: Safe train position, Digital Register, Train position report
Digital Register
The Digital Register is a shared source of reliable static infrastructure data. It supports systems such as TMS, Plan Execution, Moving Block, ASTP, ATO and DATO components by ensuring that infrastructure data are consistent, current and usable across the system architecture.
Related articles: From Fixed Blocks to Moving Block, Railway Automation: From Automatic Driving to Autonomous Operation, A systemic approach to DATO
See also: Digital Map, ASTP, Moving Block System
Digital Automatic Coupler / DAC
The Digital Automatic Coupler is a freight train coupling technology intended to provide automated coupling and digital continuity along freight trains. In the context of HTD and Moving Block, it can become an enabler for train integrity, train length and freight migration.
Related articles: From Fixed Blocks to Moving Block
See also: Train integrity, Train length, Freight migration
Electro-pneumatic braking
Electro-pneumatic braking uses electrical control to trigger pneumatic braking more rapidly and more consistently along the train. It is especially relevant for long freight trains, where conventional pneumatic brake propagation can be slow.
Related articles: From Fixed Blocks to Moving Block
See also: DAC, Freight migration, Braking curve
5. ERTMS/ATO and automatic driving
Automatic Train Operation / ATO
Automatic Train Operation is a method of operation in which different train operation tasks are automated according to the Grade of Automation. In the ERTMS context, ATO and ERTMS/ATO have the same meaning.
Related articles: Automatic Train Operation, ERTMS/ATO
See also: GoA2, ATO onboard, ATO trackside, Journey Profile
ERTMS/ATO
ERTMS/ATO is the ATO part of ERTMS. It enables interoperable automatic train operation by allowing ATO onboard and ATO trackside to exchange operational and infrastructure data while ETCS continues to provide train protection.
Related articles: ERTMS/ATO, Automatic Train Operation
See also: ATO onboard, ATO trackside, Journey Profile, Segment Profile
ATO onboard / ATO-OB
ATO onboard is the subsystem and set of automated non-safety-related driver functions, depending on the Grade of Automation. It calculates and follows the driving strategy, typically by controlling traction and braking within the ETCS safety envelope.
Related articles: Automatic Train Operation, ERTMS/ATO
See also: ATO trackside, Journey Profile, ATO Operational Speed Profile
ATO trackside / ATO-TS
ATO trackside is the set of functions that interfaces with the trackside systems containing the operational and infrastructure data required by ATO onboard. It provides the data needed for interoperable automatic driving.
Related articles: ERTMS/ATO, Traffic Management System
See also: ATO onboard, Journey Profile, Segment Profile, TMS
ATO Area
An ATO Area is an area where, for GoA2 to GoA4, Automatic Train Operation is possible and informed by real-time dynamic updates of operational data through a telecommunications link between ATO onboard and ATO trackside.
Related articles: ERTMS/ATO
See also: ATO onboard, ATO trackside, GoA2
ATO Operational Speed Profile
The ATO Operational Speed Profile is the most energy-efficient speed profile calculated by ATO onboard that fulfils the Journey Profile and respects the ETCS safe braking envelope.
Related articles: ERTMS/ATO
See also: Journey Profile, Speed profile, Braking curve
ATO Fitted Train
An ATO Fitted Train is a train fitted with an ATO onboard subsystem. It is not necessarily operating under ATO at all times; it has the required onboard equipment.
Related articles: ERTMS/ATO
See also: ATO Operated Train, ATO onboard
ATO Operated Train
An ATO Operated Train is a train fitted with ATO onboard equipment where the subsystem is operational. The train can therefore be operated using ATO functions under the relevant conditions.
Related articles: ERTMS/ATO
See also: ATO Fitted Train, ATO onboard
Non-ATO Train
A Non-ATO Train is either not equipped with ATO or has inoperative ATO onboard equipment. Mixed traffic with ATO and non-ATO trains is an important migration and capacity issue.
Related articles: ERTMS/ATO, Traffic Management System
See also: ATO Operated Train, Migration architecture
Journey
A Journey is the scheduled movement of a vehicle along a single route. In ERTMS/ATO, the Journey is described through data that allow ATO onboard to drive according to operational and infrastructure constraints.
Related articles: ERTMS/ATO
See also: Journey Profile, Segment Profile, Timing Point
Journey Profile / JP
The Journey Profile describes the information needed by the train to know the path it should take, timetable information and temporary constraints. It contains operational data required by ATO onboard to follow the planned journey.
Related articles: ERTMS/ATO, Traffic Management System
See also: Segment Profile, Timing Point, TPE
Segment Profile / SP
A Segment Profile is a one-dimensional object describing a single consecutive section of track. It corresponds to the track centreline of that section and provides static infrastructure data required by ATO onboard.
Related articles: ERTMS/ATO, Traffic Management System
See also: Journey Profile, Digital Register, Timing Point
Timing Point / TP
A Timing Point is a location defined in the Segment Profile for which a type and a specific time are identified in the Journey Profile. It may be a stopping point or a passing point and is used by TMS or ATO for operational control.
Related articles: ERTMS/ATO, Traffic Management System
See also: Journey Profile, Segment Profile, Passing Point, Stopping Point
Stopping Point
A Stopping Point is a Timing Point where the train is planned to stop within a given time window, usually to allow passengers to board or alight or to perform another operational activity.
Related articles: ERTMS/ATO
See also: Timing Point, Dwell Time, Stopping accuracy
Passing Point
A Passing Point is a Timing Point where the train is planned to pass within a given time window defined in the Journey Profile, without stopping.
Related articles: ERTMS/ATO, Traffic Management System
See also: Timing Point, Journey Profile, Train Path Envelope
Dwell Time
Dwell Time is the time during which a train is stopped at a Stopping Point, from wheel stop to wheel start. It is an important capacity factor, especially in dense passenger operations.
Related articles: ERTMS/ATO, Traffic Management System
See also: Stopping Point, Minimum Dwell Time, Capacity envelope
Minimum Dwell Time
Minimum Dwell Time is the minimum allowed dwell time at a Stopping Point included in the Journey Profile. ATO onboard considers it before departure, both in normal operation and during degraded operation or service recovery.
Related articles: ERTMS/ATO
See also: Dwell Time, Stopping Point, Journey Profile
Stopping accuracy
Stopping accuracy is the ability of a train to stop at a precise location. It is important for passenger service, platform screen doors, platform alignment and high-quality ATO operation.
Related articles: Automatic Train Operation, ERTMS/ATO
See also: Stopping Point, ATO, Journey Profile
Energy-efficient driving
Energy-efficient driving is a driving strategy that reduces energy consumption while respecting the timetable, signalling constraints and operational requirements. ATO and C-DAS can support energy-efficient operation by optimising traction and braking.
Related articles: Automatic Train Operation, ERTMS/ATO
See also: ATO Operational Speed Profile, C-DAS, Train trajectory
C-DAS
C-DAS stands for Connected Driver Advisory System. It provides real-time driving advice to the driver based on operational and infrastructure data, while the driver remains in control of traction and braking.
Related articles: Automatic Train Operation, Traffic Management System
See also: DAS, ATO, Train Path Envelope
6. Traffic Management and operational planning
Traffic Management System / TMS
A Traffic Management System supports the supervision, planning, conflict detection, regulation and replanning of railway traffic. In automated railway operation, TMS becomes a key orchestration layer between the timetable, infrastructure, trains, ATO and operational decisions.
Related articles: Traffic Management System, ERTMS/ATO
See also: RTTP, TPE, Conflict detection, Replanning
Operational plan
The operational plan is the current plan for train movements, routes, timing points and constraints. It may be derived from the timetable but updated according to real-time traffic conditions.
Related articles: Traffic Management System
See also: RTTP, TMS, Plan Execution
Real-Time Traffic Plan / RTTP
The Real-Time Traffic Plan is the operational timetable based on planned routes and timing points, updated according to the current traffic situation and potential delays. It provides the operational basis from which constraints can be sent to ATO or C-DAS.
Related articles: Traffic Management System, ERTMS/ATO
See also: Operational plan, TPE, Journey Profile
Train Path Envelope / TPE
The Train Path Envelope is a set of timing points with time targets or windows, and possibly speed targets or windows, used as constraints for onboard train trajectory generation in ATO or C-DAS.
Related articles: Traffic Management System, ERTMS/ATO
See also: Journey Profile, Train trajectory, RTTP
Train trajectory
A train trajectory is the time and speed profile over distance for a specific route, complying with train, track and operational constraints. In ATO or C-DAS, the trajectory should fit within the Train Path Envelope to support conflict-free operation.
Related articles: Traffic Management System, ERTMS/ATO
See also: TPE, ATO, C-DAS
Conflict detection
Conflict detection is the identification of potential incompatibilities between planned or actual train movements. It is a core TMS function and becomes increasingly important when railways operate closer to capacity limits.
Related articles: Traffic Management System
See also: Conflict resolution, Replanning, TMS
Conflict resolution
Conflict resolution is the process of selecting and applying operational decisions to remove or mitigate conflicts between train movements. It may involve reordering, retiming, rerouting or modifying operational constraints.
Related articles: Traffic Management System
See also: Conflict detection, Replanning, RTTP
Replanning
Replanning is the process of updating the operational plan when traffic conditions change. It is essential for handling delays, disruptions, infrastructure constraints and degraded situations.
Related articles: Traffic Management System, Remote Driving
See also: RTTP, Conflict resolution, Dynamic replanning
Operational feedback
Operational feedback is information returned from trains or operational systems to the TMS, such as status, location, forecasts and expected arrival times. It enables dynamic replanning and improved conflict detection.
Related articles: Traffic Management System
See also: TMS, ATO, Train trajectory
Plan Execution / PE
Plan Execution is the function that translates an operational plan into executable requests for the signalling or control system. In Moving Block architectures, it can form a link between TMS and the Moving Block System.
Related articles: From Fixed Blocks to Moving Block, Traffic Management System
See also: TMS, MBS, Operational plan
7. DATO and system architecture
DATO
DATO stands for Digital and Automated up to Autonomous Train Operation. It refers to the European railway automation trajectory from digital and automatic train operation towards autonomous operation, including GoA3/4 capabilities and system-of-systems architecture.
Related articles: Railway Automation: From Automatic Driving to Autonomous Operation, A systemic approach to DATO
See also: GoA4, System-of-systems, ADM, APM, PER
Autonomous train
An autonomous train is a train that can perform train operation functions without relying on a driver onboard. In the Voie Libre approach, the autonomous train should not be understood only as a train that drives itself, but as part of a broader railway system that reallocates operational responsibilities.
Related articles: Railway Automation: From Automatic Driving to Autonomous Operation
See also: GoA4, DATO, Autonomous railway operation
Autonomous railway operation
Autonomous railway operation refers to the ability of the railway system to operate safely and effectively without relying on onboard staff for the responsibilities historically performed in the cab. It includes train automation, supervision, degraded-mode management, operational decision-making and recovery.
Related articles: Railway Automation: From Automatic Driving to Autonomous Operation, A systemic approach to DATO
See also: GoA4, DATO, Remote supervision
Automatic Driving Module / ADM
The Automatic Driving Module is a DATO logical component associated with automatic train driving functions. It supports the execution of train movement according to the mission, constraints and automation architecture.
Related articles: Railway Automation: From Automatic Driving to Autonomous Operation, A systemic approach to DATO
See also: ATO, APM, Mission Profile
Automatic Processing Module / APM
The Automatic Processing Module is a DATO logical component associated with onboard processing, decision support or automated actions that contribute to functions historically performed by the driver.
Related articles: Railway Automation: From Automatic Driving to Autonomous Operation, A systemic approach to DATO
See also: ADM, PER, DATO
Perception / PER
PER is a perception component used in DATO and migration architectures. In Lineside Signalling Interpretation, PER acquires light signal aspect information; in GoA4 concepts, perception supports the replacement of functions historically performed by the driver’s observation.
Related articles: Migration to ERTMS/ATO, Railway Automation: From Automatic Driving to Autonomous Operation
See also: SCV, Signal aspect, Mediated perception
Repository / REP
REP is a repository or onboard data component used in DATO architectures to provide relevant infrastructure, operational or mission-related data to onboard automation functions.
Related articles: Railway Automation: From Automatic Driving to Autonomous Operation, Migration to ERTMS/ATO
See also: Digital Map, Digital Register, Segment Profile
Train Control and Monitoring System / TCMS
The Train Control and Monitoring System is the rolling stock system that supervises and controls train functions and provides train status information. It becomes increasingly important in GoA4 and Remote Driving because onboard train functions must be digitally accessible and monitored.
Related articles: Railway Automation: From Automatic Driving to Autonomous Operation, Remote Driving
See also: Intelligent rolling stock, Train health monitoring, Remote control onboard
Intelligent rolling stock
Intelligent rolling stock refers to trains equipped with digital onboard systems able to provide diagnostics, train status, automated workflows and interfaces with external systems. It is a key enabler for GoA4, Remote Driving and DATO.
Related articles: Railway Automation: From Automatic Driving to Autonomous Operation, Remote Driving
See also: TCMS, Train health monitoring, Mission fitness
Train health monitoring
Train health monitoring is the continuous or periodic assessment of the technical condition of the train. In automated and remote operation, the system must know whether the train is fit to start, continue or complete its mission.
Related articles: Railway Automation: From Automatic Driving to Autonomous Operation, Remote Driving
See also: TCMS, Mission fitness, Self-tests
Mission Profile
A Mission Profile describes the operational mission to be executed by the train, including relevant route, timing and operational constraints. It is a key concept for higher Grades of Automation and DATO architectures.
Related articles: Railway Automation: From Automatic Driving to Autonomous Operation
See also: Journey Profile, ADM, DATO
Mission fitness
Mission fitness is the ability of a train to perform a given mission under the required operational and technical conditions. It depends on train health, available systems, route constraints and the operational domain.
Related articles: Railway Automation: From Automatic Driving to Autonomous Operation, Remote Driving
See also: Train health monitoring, TCMS, Operational domain
Operational domain
The operational domain defines the conditions under which an automated or remotely controlled function is allowed to operate. It may include infrastructure, speed, weather, visibility, signalling, traffic, rolling stock status and communication conditions.
Related articles: Railway Automation: From Automatic Driving to Autonomous Operation, Remote Driving
See also: GoA4, Remote driving envelope, Degraded mode
Lineside Signalling Interpretation / LSI
Lineside Signalling Interpretation is a migration architecture that allows ERTMS/ATO to be used on lines not yet equipped with ETCS trackside. The train perceives a light signal aspect onboard, converts it into ETCS-compliant data and reuses standard ERTMS/ATO as far as possible.
Related articles: Migration to ERTMS/ATO
See also: PER, SCV, Light signal, Migration architecture
Signalling Converter / SCV
The Signalling Converter is a component that translates perceived light signal aspect information into ERTMS/ETCS-compliant information. It uses localisation and digital map data to support Lineside Signalling Interpretation.
Related articles: Migration to ERTMS/ATO
See also: PER, Digital Map, Signal aspect
Digital Map
A Digital Map is a digital representation of infrastructure data used by onboard or trackside systems. In Lineside Signalling Interpretation, it helps the system associate perceived signal aspects with the relevant ETCS-compliant data.
Related articles: Migration to ERTMS/ATO, Railway Automation: From Automatic Driving to Autonomous Operation
See also: Digital Register, Localisation, SCV
Localisation
Localisation is the process by which the train determines its position on the infrastructure. It is essential for ETCS, ATO, Lineside Signalling Interpretation, ASTP and train-centric capacity concepts.
Related articles: Migration to ERTMS/ATO, From Fixed Blocks to Moving Block
See also: ASTP, Odometry, Safe train position
Migration architecture
A migration architecture is an intermediate system architecture that enables progressive deployment towards a target architecture. In railway automation, migration architectures are needed because rolling stock, signalling and infrastructure cannot be transformed overnight.
Related articles: Migration to ERTMS/ATO, From Fixed Blocks to Moving Block
See also: Lineside Signalling Interpretation, HTD, Legacy signalling
8. Remote Driving
Remote Driving
Remote Driving is the remote operation of a train by a human driver located outside the train. It is not autonomous operation: the driver remains responsible for driving, but the driving interface, perception and control are moved to a remote environment.
Related articles: Remote Driving
See also: Remote Driver, Remote Supervision Centre, Handover of control
Remote Driver
A Remote Driver is a qualified person who drives or controls a train from a remote workstation rather than from the cab. The remote driver depends on mediated perception, communication links and remote access to train functions.
Related articles: Remote Driving
See also: Train Driver, Mediated perception, Remote driving workstation
Remote Supervision Centre / RSC
A Remote Supervision Centre is an operational facility from which remote supervision, remote driving or exception handling can be performed. It may include remote driving workstations, traffic information, video feeds, train status and communication systems.
Related articles: Remote Driving, Railway Automation: From Automatic Driving to Autonomous Operation
See also: Remote Driver, Remote supervision, TMS
Remote driving workstation
A remote driving workstation is the interface used by a Remote Driver to control a train from a remote location. It may include video, audio, train status, command interfaces, signalling information and operational communication.
Related articles: Remote Driving
See also: Remote Driver, Mediated perception, Remote command
Remote command
A remote command is a command sent from a remote workstation or control centre to the train. Because it may affect train movement or train functions, it requires strong safety, cybersecurity, authentication, authorisation and traceability principles.
Related articles: Remote Driving
See also: Cybersecurity, Command channel, Authentication
Mediated perception
Mediated perception is perception of the train environment through technical means such as video, audio, sensors or data interfaces rather than direct human observation from the cab. It is a key human factors challenge in Remote Driving.
Related articles: Remote Driving
See also: Direct perception, Remote Driver, Human factors
Direct perception
Direct perception is the driver’s perception of the environment from the cab through vision, sound, vibration and physical presence onboard. Remote Driving replaces part of this perception with mediated perception.
Related articles: Remote Driving
See also: Mediated perception, Train Driver, Human factors
Handover of control
Handover of control is the transfer of control authority between actors or systems, such as from onboard driver to remote driver, or from automated system to remote driver. It must avoid ambiguous states where responsibility is unclear.
Related articles: Remote Driving, Railway Automation: From Automatic Driving to Autonomous Operation
See also: Responsibility allocation, Takeover, Fallback
Takeover
Takeover is the moment when a person or system assumes control of a train or function from another person or system. In Remote Driving and GoA4, takeover procedures must be clearly defined, safe and traceable.
Related articles: Remote Driving
See also: Handover of control, Fallback, Remote Driver
Fallback
Fallback is an alternative operating mode or procedure used when the nominal system or function is not available. Remote Driving can act as a fallback capability for some GoA4 degraded situations.
Related articles: Remote Driving, Railway Automation: From Automatic Driving to Autonomous Operation
See also: Degraded mode, Recovery mode, Takeover
Operational envelope
An operational envelope defines the conditions within which a train, automated system or remote driving function may operate. It may include speed, route, visibility, communication quality, train status, weather and signalling conditions.
Related articles: Remote Driving, Railway Automation: From Automatic Driving to Autonomous Operation
See also: Operational domain, Remote driving envelope, Mission fitness
Remote driving envelope
The remote driving envelope defines the conditions under which Remote Driving may be used safely and operationally. It may be narrower than the full operational domain of the train, especially in early deployment.
Related articles: Remote Driving
See also: Operational envelope, Remote Driving, Degraded mode
Technical train movement
A technical train movement is a non-passenger movement required for operation, such as moving a train from depot to platform, from platform to yard, or between stabling tracks. Remote Driving can improve the productivity of such movements.
Related articles: Remote Driving
See also: Empty stock movement, Business continuity, Remote Driving
Empty stock movement
An empty stock movement is the movement of a train without passengers, often between depot, yard, platform or stabling location. These movements can consume significant driver time despite being operationally short.
Related articles: Remote Driving
See also: Technical train movement, Remote Driving, Business continuity
Business continuity
Business continuity is the ability to maintain service or essential operations despite constraints, disruptions or resource shortages. Remote Driving can support business continuity by reducing scarce driver time consumed by low-value technical movements.
Related articles: Remote Driving
See also: Technical train movement, Driver shortage, Operational resilience
Human factors
Human factors refer to the interaction between humans, technology, procedures and operating environment. In Remote Driving, they include vigilance, mediated perception, responsibility, workload, trust, loss of physical cues and possible gamification effects.
Related articles: Remote Driving
See also: Mediated perception, Remote Driver, Responsibility allocation
Cybersecurity
Cybersecurity is the protection of digital systems, communication channels, data and commands against unauthorised access, manipulation or disruption. It is critical for Remote Driving, DATO, ETCS communication and train-centric architectures.
Related articles: Remote Driving, Railway Automation: From Automatic Driving to Autonomous Operation
See also: Authentication, Authorisation, Remote command
Authentication
Authentication is the process of determining whether someone or something is who or what it claims to be. In railway digital systems, it supports secure communication, key management and protection against unauthorised access.
Related articles: ERTMS/ETCS, Remote Driving
See also: Cybersecurity, Remote command, Euroradio
Authorisation
Authorisation is the process of determining whether an authenticated person, system or function is allowed to perform a given action. In Remote Driving, it is essential to ensure that only the right actor can take control or send commands.
Related articles: Remote Driving
See also: Authentication, Handover of control, Cybersecurity
Traceability
Traceability is the ability to record and reconstruct actions, commands, status changes and decisions. It is essential for safety analysis, incident investigation, cybersecurity and responsibility management in automated or remote operation.
Related articles: Remote Driving
See also: Juridical data, Remote command, Responsibility allocation
9. European framework and programmes
Technical Specification for Interoperability / TSI
A Technical Specification for Interoperability defines European requirements for a subsystem of the railway system. TSIs are used to support interoperability across the European railway area.
Related articles: ERTMS, ERTMS/ETCS
See also: TSI CCS, TSI LOC&PAS, TSI OPE
TSI CCS
TSI CCS is the Technical Specification for Interoperability for Control-Command and Signalling. It is the key European regulatory framework for ERTMS/ETCS and signalling interoperability.
Related articles: ERTMS/ETCS, From Fixed Blocks to Moving Block
See also: CCS, ETCS, ERTMS
CCS
CCS stands for Control-Command and Signalling. It refers to the railway domain covering signalling, train protection, communication and control-command systems such as ETCS.
Related articles: ERTMS/ETCS, Remote Driving
See also: TSI CCS, ETCS, Interlocking
LOC&PAS
LOC&PAS refers to the rolling stock subsystem for locomotives and passenger rolling stock. It is relevant to Remote Driving and GoA4 because automated and remote functions interact with train systems, TCMS, braking, doors, diagnostics and onboard interfaces.
Related articles: Remote Driving, Railway Automation: From Automatic Driving to Autonomous Operation
See also: TCMS, Rolling stock, Train functions
OPE
OPE refers to the operation and traffic management subsystem. It is relevant to railway automation because changes in GoA, Remote Driving and DATO affect operational rules, responsibilities, degraded modes and traffic management.
Related articles: Traffic Management System, Remote Driving
See also: TMS, Operational responsibility, Degraded mode
Europe’s Rail / EU-Rail
Europe’s Rail is the European railway research and innovation programme supporting the development of future rail technologies, including automation, digital signalling, DATO, capacity and system architecture.
Related articles: A systemic approach to DATO, From Fixed Blocks to Moving Block
See also: FP1-MOTIONAL, FP2-R2DATO, System Pillar
FP1-MOTIONAL
FP1-MOTIONAL is a Europe’s Rail flagship project dealing with traffic management, capacity, automation and operational planning topics. Its work is relevant to TMS, ATO/C-DAS, Train Path Envelope and capacity simulation.
Related articles: Traffic Management System, ERTMS/ATO
See also: TMS, RTTP, TPE, C-DAS
FP2-R2DATO
FP2-R2DATO is a Europe’s Rail flagship project focused on rail digitalisation and automated up to autonomous train operation. Its work is relevant to GoA3/4, DATO, Moving Block, ASTP, Digital Register, train integrity and system architecture.
Related articles: A systemic approach to DATO, Railway Automation: From Automatic Driving to Autonomous Operation, From Fixed Blocks to Moving Block
See also: DATO, ASTP, Moving Block System, Digital Register
ERA
ERA, the European Union Agency for Railways, contributes to the development of a safe and interoperable European railway area. It plays an important role in the regulatory framework around ERTMS, TSIs and railway safety.
Related articles: ERTMS, ERTMS/ETCS
See also: TSI, TSI CCS, Interoperability
UNISIG
UNISIG is the industrial consortium involved in the specification of ERTMS/ETCS. It contributes to the technical specifications that define the interoperable ETCS system.
Related articles: ERTMS/ETCS
See also: ETCS, SUBSET-023, SUBSET-026