The $46 billion China-Pakistan Economic Corridor (CPEC) also includes building transport corridors to connect Gwadar Port in Pakistan to China through the western Chinese city of Kashghar. Afghanistan, the Islamic Republic of Iran and India concluded a trilateral agreement in 2016 to develop Chabhar Port in Iran to serve Afghanistan and Central Asia connecting it with INSTC. To maximize the network externalities or synergies, extended corridors following trunk route-feeder links, connecting more countries than just the members of a particular group, are more appropriate. The Asian Highway (AH) and Trans-Asian Railway (TAR) networks, developed by UNESCAP and backed by a series of intergovernmental agreements, offer the possibility of joining subregional corridors.