Bangkok Expressway and Metro Public Company Limited is a Thailand-based company, which is principally engaged in the construction and management of expressways, the operation of metro services and commercial development. The Company's business segments include Expressway, Rail, and Commercial development. The Expressway business segment relates to the construction and operation of the expressway. The Rail business segment relates to the operation of the rapid transit system. The Commercial development business segment relates to the rental of retail space, and the provision of advertising media services and telecommunication services inside and outside underground train stations and on expressways. Its expressway business includes Si Rat Expressway, Prachim Ratthaya Expressway, and Udon Ratthaya Expressway. The Company has three mass rapid transit rail system projects: M.R.T. Chaloem Ratchamongkhon Line Project, M.R.T. Chalong Ratchadham Line Project, and MRT Orange Line Project.