Flagger training and certification requirements

From Colorado Department of Transportation (CDOT) Flagger Program website:
“In accordance with C.R.S. 43-5-308(2)(a) and 43-5-308(3)(b), a Flagger must be trained by an entity authorized by CDOT prior to providing temporary traffic control or direction within any highway, road, or street maintenance or construction work area;
… …
Flagger certifications in and for Colorado are valid for two years. Flagger certifications from ATSSA and NSC are valid in Colorado but are only valid for two years from date of issuance.”