National Highway 31A connects Sivok in West Bengal
with the capital city of Sikkim
. This highway starts at the junction with National Highway 31 at Sivok and travels northwards for 30 km, before entering Sikkim at Rangpo
. Those venturing to Darjeeling
need to turn west and east respectively at the respective points on the National Highway 31A. In Sikkim, National Highway 31A traverses 62 km, before terminating at Gangtok; Ratong is situated on the highway.