The distrance between Trashigang and Samdrup Jongkhar 180 km and takes 6 to 7 hours drive to reach. The highway was constructed in 1960s and aided opening up of eastern Bhutan to the outside world, resulting in increased trade with neighboring Assam state. Samdrup Jongkhar is the entry and exit points to and from the airport from Guwahati (India), the capital of Assam, which is 101 km from Samdrup Jongkhar. Next professional personal statement writers uk.