Assam State Transport Corporation or ASTC is a state owned road transport corporation of Assam, which provides bus services within Assam and adjoining states. Assam State Transport was started as a State Government Department with four buses to run between Guwahati and Nagaon. Gradually the transport network of the department expanded throughout the state of Assam. The state transport department was converted to a corporation on 30 March 1970. All buses have the registration code AS-20.