CH. Karnchang Public Company Ltd. ITALIAN-THAI Development Public Company Ltd.
Department of Highways
Department of Rural Roads

Bangkok Expressway Public Company Ltd. Electricity Generating Authority of Thailand (EGAT) Department of Groundwater Resources Airport of Thailand (AOT)

Royal Irrigation Department Bangkok Metropolitan Administration Metropolitan Waterworks Authority (Thailand) Expressway Authority of Thailand

Department of Public Works and Town & Country Planning
State Railway of Thailand Office of Transport and Traffic Policy and Planning (OTP)