In all cases where any part of the state highway system extends into or through a city or incorporated town, the construction and maintenance of such systems shall remain the obligation of the department of transportation. Nothing in this part 1, however, shall be construed as denying the department of transportation the right to enter into a contract with a city or incorporated town for the maintenance or construction of such urban connections, where it appears that such city or incorporated town has adequate facilities.
C.R.S. § 43-2-103
For similar provisions, see § 43-1-217(2).