The South Line of Chennai Suburban Railway is the fourth longest suburban line that runs southwards from Chennai (Madras) City. It is the oldest suburban line of Chennai (Madras), opened in 1931. Suburban services terminate at Chengalpattu (Chingleput) and MEMU services at Villupuram. The capacity utilisation of Chennai Beach-Egmore-Tambaram section is 69 percent. The tract travels along the GST Road from St.Thomas Mount to Villupuram.