Mumbai, April 4 -- Railway authorities have proposed the construction of a new rail corridor and expansion of two existing lines that will help segregate suburban and long-distance trains and also strengthen the mass transit system in the regions of Panvel, Navi Mumbai, Vasai-Virar and north of Kalyan, HT has learnt. The projects, estimated to cost Rs.12,500 crore, are part of phase 3B of the Mumbai Urban Transport Project (MUTP)....