of Thailand's GDP. Surat Thani province had an economic output of 206.869 billion baht (US$6.67 billion). This equates to a GPP per capita of 182,371 baht (US$5,883), more than double for Yala province, which is fifth and more than three times for Narathiwat province, lowest in the ranking. Kamphaeng Phet province had an economic output of 117.705 billion baht (US$3.8 billion). This amounts to a GPP per capita of 150,783 baht (US$4,864), half more than for Tak province, which is fifth in the ranking. Transportation Southern Thailand is connected with Bangkok by railway as well as highway. Several regional airports are located at the larger towns. The transportation hub of all south Thailand is Hat Yai. Road Phetkasem Road is the longest road in Thailand, running from Bangkok along the Kra Isthmus and then along the west coast of the peninsula. From Trang it crosses over to the east coast to Hat Yai, and ends at the Malaysian border. Two Asian highways run through Southern Thailand: Asian Highway 2 runs mostly parallel to the railroad all the way from Bangkok. It crosses to Malaysia at Sadao, and continues on the west side of the peninsula. Asian Highway 18 begins in Hat Yai and runs south along the east coast, crossing to Malaysia at Sungai Kolok. Rail The southern railway connects Bangkok to Hat Yai, and continues from there to Sungai Kolok. There are branches from Ban Thung Phoe Junction to Kirirat Nikhom. Two smaller branches of the railway run from Thung Song to Trang and Nakhon Si Thammarat, and from Hat Yai Junction to Malaysia and Singapore. Air Southern Thailand has five international airports and six domestic airports. Thailand's transport ministry is constructing the 1.9 billion baht Betong Airport. It is scheduled for completion in 2020. Chumphon Airport Hat Yai International Airport Krabi International Airport Nakhon Si Thammarat Airport Narathiwat Airport Pattani Airport Phuket International Airport Ranong Airport Ko Samui International Airport Surat Thani International Airport Trang Airport See also South Thailand insurgency Yawi language OK Betong — Thai film set in Southern Thailand. References Further reading Suthiwong Pongpaiboon. Southern Thai Cultural Structures and Dynamics Vis-à-vis Development. . External links . Regions of Thailand