Certification requirements for personnel designing and setting up work zone traffic control

In Colorado, traffic control (or work zone) supervisors must be ATSSA or CCA (Colorado Contractors Assn) certified. Duties of the traffic control supervisor include oversight of the day-to-day planning, design, installation, and maintenance of the work zone.
Design and construction management people (both CDOT and contractors) are not required to have certification, but many of those involved in design of traffic control plans have been certified.