Portable changeable message signs are normally mounted on trailers so that they can be towed to and left at a specific location for a temporary need. They are used for construction projects, maintenance projects, special events, and emergency situations. They are an effective and versatile tool for responding to changing or temporary traffic management situations. For more information on the use of portable changeable message signs, see the Barricade and Construction Traffic Engineering Standard Sheets.

of the Texas Transportation Code requires TxDOT to actively manage a system of dynamic message signs to provide current information to the traveling public. Dynamic message signs are normally mounted on freeways to provide timely messages to motorists. They are used where special conditions indicate a need to provide this extra level of information.

TxDOT does not install bilingual signs on the state highway system. This is due to the multiple ethnicities and various dialects across the state. TxDOT will only install bilingual signs at safety inspection facilities located at the border of Mexico and Texas. These bilingual signs are placed to direct commercial motor vehicles to the various functions of these border facilities.