Plans for mass transit railways in Korat and Phuket have been discussed at times, but officials have so far said Phuket.
Bangkok Mass Transit Railway (Skytrain)
Elevated 2 lines, 23 stations, 23 km where the homeless sleep on the islands
Be sure to check out Ron Morris' great Bangkok subway and skytrain sites
Bangkok MTR (Mass Transit
Railway), aka Blue line, aka the new subway
The Unofficial Chiang Mai Subway Site - Mystery subway plans in Bangkok by Ron Morris
The Consulting Engineers Association of Thailand (CEAT) MTR page
THE UNOFFICIAL CHIANG MAI SUBWAY SITE
There also exists a project called the Bangkok Elevated Road and Train System. Some information about this system exists on Ove Arup & Partners' site, as well as on Siemen's site.
Finally, a .
The Dawn of Rapid Transit in Bangkok