What is GoA 4 in trains?

GoA 4 stands for Grade of Automation 4, also known as Unattended Train Operation (UTO). In this mode, the train operates entirely without staff on board. Starting, stopping, door operation, and emergency responses are all handled by the system and supervised remotely.

Are driverless trains safer than human-driven trains?

Statistically, yes. Automated systems eliminate human error, which is the leading cause of railway accidents (such as speeding or ignoring signals). Systems like ATP and ATO ensure the train never exceeds safe limits.

What is the difference between GoA 2 and GoA 3?

The main difference is the presence of a driver in the front cab. In GoA 2 (Semi-automated), a driver is in the cab to close doors and start the train. In GoA 3 (Driverless), there is no driver in the front, but an attendant is present somewhere in the passenger area to assist if needed.

Do driverless trains need special tracks?

They don't necessarily need special rails, but they require advanced signaling systems (like CBTC) and usually require Platform Screen Doors at stations to ensure no one falls onto the tracks, as there is no driver to watch the line.

The Ghost in the Machine: Mastering Driverless Train Levels (GoA)

From manual control to “ghost trains.” Discover the IEC 62290 standard and the 4 Grades of Automation (GoA) that define the future of driverless mass transit.

December 10, 2025 1:33 pm

What are GoA Levels?

GoA (Grades of Automation) is the international standard (IEC 62290) used to classify the level of automation in railway operation. It ranges from GoA 0 (on-sight manual driving like a tram) to GoA 4 (fully unattended operation). These levels define strictly “who does what” between the human driver and the computer system regarding starting, stopping, door operation, and emergency handling.

The 4 Grades of Automation Explained

The progression towards autonomy is broken down into four distinct steps:

GoA 1 (Non-Automated): The driver drives manually but is protected by an ATP system that automatically applies brakes if the train speeds or passes a red signal.
GoA 2 (Semi-Automated): The train accelerates and brakes automatically (ATO), but a driver sits in the cab to close doors and initiate the departure. Most older metro lines operate here.
GoA 3 (Driverless – DTO): No driver is in the cab. The train runs automatically, but a “train attendant” is present on board to handle emergencies or passenger control.
GoA 4 (Unattended – UTO): The “Holy Grail” of automation. No staff is required on the train. The system handles everything, including emergencies, often managed remotely from the OCC.

Comparison: Responsibilities at Each Level

The shift from human to machine responsibility allows for shorter headways (time between trains) and consistent energy usage.

Operation Task	GoA 1 (Manual)	GoA 2 (Semi-Auto)	GoA 4 (Unattended)
Acceleration/Braking	Driver	System (ATO)	System (ATO)
Door Closure	Driver	Driver	System
Emergency Recovery	Driver	Driver	System / Remote OCC
Staff Onboard	Driver in Cab	Driver in Cab	None
Infrastructure	Standard Signals	Cab Signaling	Requires Platform Screen Doors

The Role of CBTC and Safety

Higher levels of automation (GoA 3 and 4) rely heavily on CBTC (Communication Based Train Control). This technology uses continuous radio communication to calculate the exact position of the train, allowing them to run closer together safely. For GoA 4 specifically, physical barriers like Platform Screen Doors (PSD) are virtually mandatory to prevent track intrusions, as there is no driver to spot a person on the rails.