Flagger training and certification requirements

From Vermont Agency of Transportation Standard Specifications for Construction:
“630.04 FLAGGERS.
(a) Requirements. The Contractor shall verify that flaggers meet the following requirements. Flaggers shall have successfully completed a 4-hour training course taught by a certified instructor within the last 24 months and shall carry proof of training at all times when on the project. Certified instructors shall have successfully completed one of the following courses:
(1) Associated General Contractors of Vermont Traffic Control Technician/Flagger Trainer Course
(2) American Traffic Safety Services Association Flagger Instructor Training Course
(3) National Safety Council Flagger Instructor Course”