2 Colo. Code Regs. § 601-10-4.23
Failure of the Low Responsible and Responsive Bidder to so execute the Contract and file acceptable Contract Bonds within fifteen calendar days or other duration specified by CDOT after the date of Award shall be just cause for the cancellation of the Award and the forfeiture of the Bid Proposal Guarantee which shall become the property of CDOT. CDOT may elect to waive forfeiture of the Bid Proposal Guarantee only if CDOT determines that the Low Responsible and Responsive has made a good faith effort, which was an honest, nonjudgmental error, not the result of intentional conduct, gross negligence or willful neglect, and that no damages were sustained by CDOT as a result of the failure by the Low Responsible and Responsive Bidder to execute the Contract and file acceptable Contract Bonds within the time prescribed. Award may then be made, in accordance with the provisions of Section 4.18 to the next lowest responsible and responsive Bidder, or the project may be re-advertised.
2 CCR 601-10-4.23