Colo. Rev. Stat. § 43-3-211
Any holder of bonds issued under the provisions of this part 2 or any of the coupons attached to said bonds and the trustee under the trust indenture, if any, except to the extent the rights given in this section may be restricted by resolution passed before the issuance of the bonds or by the trust indenture, either at law or in equity by suit, action, mandamus, or other proceedings, may protect and enforce any and all rights granted under this section or under such resolution or trust indenture and may enforce and compel performance of any duties required by this part 2 or by such resolution or trust indenture to be performed by the department of transportation or any officer thereof, including the fixing, charging, and collecting of fees, fares, and tolls for the use of the turnpike project.
C.R.S. § 43-3-211