Erik Harms Saigon's Edge: On the Margins of Ho Chi Minh City 2011 Page 90 "This section of National Highway 22 was being upgraded into the Vietnam section of the Trans-Asia Highway, the Xuyên Á. It continued past Củ Chi to the border post at Mộc Bài in Tây Ninh province and eventually on to distant Phnom Penh, ...