National Highway 138 is a national highway of India.
This highway connects Palayamkottai in Tirunelveli city to V.O. Chidambaranar Port Authority in Thoothukudi city. This route provides quick transportation of goods from Tirunelveli to V.O. Chidambaranar Port Authority in Thoothukudi. It provides a direct route to the port and is 54 km in length.
Tuticorin Airport in also situated on this highway near Vagaikulam. The airport is situated 26 km from Thoothukudi city and 28 km from Tirunelveli city.