Colorado Revised Statutes Title 43. Transportation § 43-2-146. Highway bypasses--public policy--when

(1) It is the public policy of the state of Colorado that where the transportation commission has authorized a highway bypass to be built around any incorporated city or town or unincorporated business community of the state of Colorado, the original state highway or state and federal highway markings shall remain on the existing highway through such incorporated city, town, or unincorporated business community and the existing highway shall be maintained, and the new bypass highway shall carry the designation “bypass” or other similar markings.

(2) In all cases where such relocation has been authorized as a part of the national system of interstate and defense highways, the original state highway may be retained as part of the state system or a new and more direct approach road may be constructed to maintain service to such incorporated city, town, or unincorporated business community. In the event a new and more direct approach road is constructed, such approach road shall be placed on the state highway system and the original state highway may be deleted from the state system as provided in section 43-2-106. The markings of the relocated system of highways shall be accomplished in accordance with the practice established under section 42-4-104, C.R.S.