This is not only about to reduce the distance!
It is primary for Rail Goods Traffic generated from Indore and Pithampur. That needs a new dedicated rail line, so that GOODS can reach mumbai with in 24 hrs! that's why Indore-Manmand Rail line is very very important for Industrial growth!
Both Khandwa-Mumbai and Surat-Mumbai rail lines has already huge traffic, Indore-Manmand Rail line is best solution for all!