The State Railway of Thailand (SRT) operates all of Thailand's national rail lines. Bangkok Railway Station (Hua Lamphong Station) is the main terminus of all routes. Phahonyothin and ICD Lat Krabang are the main freight terminals. SRT had of track, all of it meter gauge except the Airport Link. Nearly all is single-track (4,097 km), although some important sections around Bangkok are double () or triple-tracked () and there are plans to extend this. Rail transport in Bangkok includes long-distance services, and some daily commuter trains running from and to the outskirts of the city during the rush hour, but passenger numbers have remained low. There are also three rapid transit rail systems in the capital.