train introduce hoti hain aur wo paper mein isliye rahejaati hai kyunki hamaare desh mein coach factory bahut kam hain, coach ki demand jyaada hai leking banti kam hai. is waqt hamare desh mein prati varsh 1000 coach kam banti hain jabki jarurat hai 4500 coach ki har saal , total 3500 coach hi ban paati hain, isliye jyaada trains railbudget mein announce ho jaati hain lekin 4 yaa 5 saal ke baad chalaayee jaati hain. aaj ke date mein bahut si train rake sharing system mein chal rahi hain.