sentences:  Some are operated by the agencies themselves; others are operated by private concessionaires.EXAT is in charge of Chaloem Mahanakhon Expressway, Si Rat Expressway, Chalong Rat Expressway, Udon Ratthaya Expressway, Burapha Withi Expressway and Kanchanphisek Outer Ring Road (southern section).DoH is in charge of Uttraphimuk Tollway (formerly Don Mueang Tollway), Motorway No.