The train track's diversion or splitting system. From here the train could get diverted to original track or second track, for the purpose of , you know, get diverted to allow second train to pass on or an express train which is already late to catch up time. It is also very famous in the older time movie where the tracks might just clip ( read Kiap ) on the heroes feet, while a train is approaching fast while the girlfriends shouts helplessly at a side or something like that. These scene always scared the crap out of our parents.