Mumbai Metro Lines 4 and 6 remain delayed nearly eight years after construction began, while Orange Line 5 advances with trial runs underway on its first phase. Who will win the title of Mumbairsquos most delayed Metro project Green Line 4 WadalaThane and Pink Line 6 Swami Samarth NagarVikhroli appear to be neck and neck in the race with neither showing signs of opening soon Orange Line 5 ThaneBhiwandiKalyan meanwhile is emerging.