mumbai - chennai is not in punctuality lists. the lines between daund - solapur - gulbarga is single diesel line even it was most congested golden quadrilateral route of indian railways that connects mumbai to south india importants cites pune , solapur , guntakal, tirupati , chennai central , chennai egmore , tiruchchirappali , madurai , bangalore , mysore , thiruvananthapur , kanniyakumari , hyderabad , secunderabad , vijaywada , vishakhapatnam , bhubaneshwar cities. but still railways is not taking interest to complete the golden quadrilateral line doubling with electrification.