National Highway 45B is fully located in state Tamil nadu in India. It runs from starting at NH 45 in Trichy and runs southwards to the port town of Tuticorin where it meets NH 7A. It has major junction points at Madurai with NH 7 and NH 49
Trichy, Viralimalai, Tovarankurichi, Melur, Madurai, Kariapatti, Aruppukottai, Pandalkudi, Kottur, Ettaiyapuram, Eppodumvenran, Kurukluchalai and Tuticorin.
Road improvement projects 
The distance of 131 km (81 mi) between Trichy and Madurai is widened into four lanes and the project is completed on May 2010. The widening of the remaining 128 km (80 mi) highway from Madurai to Thoothukudi is also completed by Madhucon Projects Ltd. and SREI - Madhucon granites Ltd. The total length of this highway is 252 km (157 mi) from Trichy to Tuticorin.