Railway minister Suresh Prabhu on Sunday inaugurated India’s first 'green train corridor' – a 114-km stretch between Rameswaram and Manamadurai in Tamil Nadu. A green corridor or zero toilet discharge section envisages that all trains on that route will have bio-toilets, thereby eliminating open discharge of waste on the tracks. Railways has provided 40,750 bio-toilets in trains, as of June-end.