AUTOMATIC TRAIN OPERATION
Automatic acceleration has long been a feature of rail transit, where relays, and more recently microprocessors, control the rate of acceleration smoothly from the initial start to maximum speed. Linking this feature to on-board commands from the signaling system provides automatic train operation.
Automated train operation systems often also provide for manual operation.
The acceptance of driverless trains in transit service has been slow.
The driver or attendant’s role is typically limited to closing the doors, pressing a train start button, and observing the line ahead, with limited manual operating capabilities to deal with certain failures. Dispensing entirely with a driver or attendant is controversial but has demonstrated its economy and safety on numerous automated guideway transit (AGT) systems, and on rail systems in Europe and Vancouver, B.C.
Automatic train operation (ATO), with or without attendants or drivers, allows a train to follow the optimum speed envelope more closely and commence braking for the final station approach at the last possible moment. This reduces station-to-station travel times, and, more importantly, from the point of capacity, it minimizes the critical station close-in time—the time from when one train starts to leave a station until the following train is berthed in that station. This can increase total line capacity by 2 to 4%.