The orange indicator light in front is to show whether it is in
auto or manual mode.
Automatic mode (AM) - no light
Coded Manual (CM) - orange light displayed
Restricted manual (RM) - blinking orange light
AM - normal train operation under Automatic Train Operation
(ATO). Driver will just open/close doors and ensure nothing
untoward happens
CM - manual driving. The driver will drive the train at the
speeds indicated by the speed code (e.g. what speed at which
stretch along the track). Normally happens in less-than-ideal train
operating conditions esp. during rains. That is why you will see
the orange light turned on during a downpour.
RM - restricted manual. The train moves veeerrrryyyy slowly, at
speeds below 18-20 kph. (A rare sight!)
