Bangkok Expressway and Metro Public Company Limited 

Bangkok Expressway and Metro Public Company Limited (BEM) is a Thai infrastructure firm primarily focused on developing and overseeing the country's expressway network and urban mass transit rail systems. The company's operations are divided into three core segments: its Expressway Business, Rail Business, and Commercial Development Business. BEM not only runs metro services but also pursues commercial opportunities associated with its extensive expressway and metro infrastructure. Its responsibilities include the management of significant expressways such as the Si Rat, Si Rat - Outer Ring Road, and Udon Ratthaya Expressways, as well as the M.R.T. Chaloem Ratchamongkhon and MRT Chalong Ratchadham Lines. Additionally, BEM generates revenue through leasing retail spaces, offering advertising services, and providing maintenance for telecommunication systems located within its metro stations. Established in 1998, the company's headquarters are situated in Bangkok, Thailand.