Transportation
The city is served by the Hat Yai International Airport.
Hat Yai Railway Station, the largest station is an international railway station in Southern Thailand. It handles 28 passenger trains per day (26 trains served by State Railway of Thailand and 2 trains (Ekspres Langkawi) are served by KTMB of Malaysia. Also it is the hub of local train in Southern Thailand.
Also parallel to the railway is the Asian highway 2. Asian highway 18 begins in Hat Yai and runs south along the eastern coast of the Malay peninsula.

History
Originally named Khok Sa-Met Choon, Hat Yai was a small village until the southern railway was built there. The junction which connected the town of Songkhla with the main route was originally located in the Utapao area, but was moved to Khok Su-Met Choon in 1922 when the Utapao area turned out to be flood prone. Khok Su-Met Choon had only four residences at that time, but due to the investments of Khun Niphatchinnkhon (謝枢泗, Jia Gi Si, 1886-1972, Hakkian Chinese), the railway contractor for the railway connection from Nakhon Si Thammarat to Pattani, it quickly grew into a small town.
In 1928 Hat Yai was made a Chumchon, which was upgraded to a sanitary district (sukhaphiban) on December 11 1935. It covered an area of 4.4 km², and was administrated by the first mayor Udom Bunlong. In 1938 the municipal administration building was completed. On March 16 1949 it was granted town status (thesaban mueang); on May 10 1961 the area covered by the municipality was increased to 8 km². Due to the continuing growth, on August 13 1968 a new larger municipal administration building was opened. On April 24 1977 the area of the municipality was enlarged a second time to 21 km². Finally in 1995 it was upgraded to city status (thesaban nakhon).
On April 3, 2005, two bomb attacks at a Carrefour department store and Hat Yai International Airport were made by Pattani separatists. The attacks killed two people and injured dozens.
On September 16, 2006 a series of bomb attacks killed four people and injured over 70. Although no-one claimed responsibility for the attacks, Pattani separatists are suspected. [1]