TCS stands for Traffic Control Supervisor.
The TCS ensures that the traffic control measures shown on the approved traffic control plans are properly implemented, operating, and documented on the project. The contractor’s TCS may not be required full time on a given project, but is required to perform all duties required by the specifications. The TCS is responsible to be on the project whenever traffic control labor is being utilized, or less frequently if authorized by the engineer.
TCT is a Traffic Control Technician.
The TCT is an apprentice position, indicating an individual who has not obtained enough hours and/or experience to be a TCS but has passed the Traffic Control Supervisors Course. The TCT can perform some of the duties of the TCS under the TCS’s supervision. (Note: The TCT is not a recognized certification in Washington; Idaho offers a separate course for a TCT.)