When you see vehicles on the road, there is always a possibility of losing the way, and getting to a wrong place. In fact, this happens often enough when a person is not familiar with the place, and can take wrong directions and end up somewhere else. After all, the way a vehicle can go is constrained only by the road surface available.
But consider the case of a train, the train moves on a track, so it can only go where the track goes; and if it steps off the track, it's mobility is very limited, almost not being able to go anywhere. It is people who move the connections between tracks that decides where the train can go, and so it has to be a human mistake if the train goes elsewhere other than where it was supposed to go.
So it was surprising when the passengers of a train found themselves going backward, and that was because the railways authority found that the train had gone off in a wrong direction and hence needed to be called back (link to article)
It was a good 6-7km before the error was spotted and the 12339 Coalfield Express started backing up slowly. Passengers knew something was wrong when they started going back the way they had come. Red-faced Eastern Railway officials admitted that the mistake could have led to a major accident. Train services have been badly affected in the east since morning due to dense fog.
It was 100 metres from Talit when station staff realized that the Coalfield Express had lost its way. The train was stopped at 7.30pm by "alert railwaymen", an official said. "There was no possibility of a head-on collision. However, had the train moved further ahead, its pantographs could have got entangled as it is a non-electrified section. It seems that those in charge mistook the Coalfield Express for some other train," an official from Burdwan Jn said.