>>49060*sigh*
I'll bite for the troll, for the sake of information.
Trains dont stop on a dime like cars or even trucks.
A long, heavy freight train can take a mile or more to completely stop when at speed.
Also it's not up to the driver or conductor to determine which specific set of tracks a given train will travel, dispatchers control that on the main lines, but most yards and lesser-used sidings are controlled by a brakeman on the ground and being even a little careless can lead to huge fuckups and accidents.
Engineers might also accidentally ignore signals, and even though there are safeties to prevent this (train comes to a stop after a period of time if a signal is not acknowledged), it still takes lots of distance to stop a train.