Whenever a freeway is designated under the provisions of this part 1, the chief engineer is authorized to lay out and construct local service roads or designate as local service roads any existing street or public way if the same is within reasonable distance of such freeway wherever, in his opinion, there is a particular danger to the traveling public of collisions due to vehicles entering the freeway from the sides thereof and may divide and separate any such service road from the freeway by raised curbs or dividing sections, or other appropriate devices. If such local service road is a highway or street already in existence, he may designate the same by appropriate signs, markers, or other devices.
C.R.S. § 43-3-105