Correct Answer - Option 3 : siding
Buffer stops or ‘snag dead ends’ are provided at the end of a siding to ensure that the vehicles stop while still on the track and do not go off it. The buffer stop is a type of barrier placed across the track which stops the vehicles from going beyond the selected point. Its essential features are the following.
(a) The buffer stop should be structurally strong to take the impact of a rolling vehicle.
(b) It should have a buffer disc with a cross-sleeper, which is normally painted red. A red lamp should be provided at its center for night indication.
(c) Normally the track should be straight for some distance near the buffer stop.
(d) It should be visible from a long distance.
A railroad switch, turnout, or set of points is a mechanical installation enabling railway trains to be guided from one track to another, such as at a railway junction.