Metro trains run without driver or guard

Driverless train will use three technologies combined in one to ensure safety of the trains against colliding   with some other train on the same track. These technologies are:1) Automatic Train Protection or ATP 2) Automatic Train Control (ATC), and 3) Automatic Train Operation (ATO)

ATP ensures that two trains always maintain a certain safe distance and if at all they come closer; there will be brake operation automatically in the following train.

ATC does setting of predetermined routes and putting on the automatic signals.

ATO will ensure which train to start from which station at what time. 

In fact ATC will respond as per the instructions given by ATO. ATP will always remain alert and in action to ensure train safety.  All these programmes are controlled by computers installed in the central control centre which of course are supervised by human beings all the time.

Not only is there one but two computers in standby mode to take over the functions in case of failures of first or second computer. Position of salient parameters, like station coordinates, grades, curves, signal positions etc are pre-fed into the computer.

Records of position and speed of the train are sent to the computer once every second through a cable laid underneath on the ground. The same cable sends instructions back to the train regarding speeding or braking, stopping or starting etc.

Sometimes a supervisor is available in the train for attending to the commuters needs but he has no contribution in the operation of the train. Such trains are in operation in a number of developed countries. In India also metro trains are run with ATP and ATC but with driver who takes over the operations as and when required.