Are the road and bridge fees charged on the Colorado vehicle registrations tax deductible?

Yes, but they are already included in your license fee. You will notice on your Colorado Registration/Ownership tax receipt right below the road fee and bridge fee that there is text stating that these fees are already included in your license fee.

Since Colorado annual vehicle registration fee is based upon the value, that amount along with the ownership tax to the left of the license fee is tax deductible on the federal portion of your income tax assuming you registered the vehicle in the state of Colorado for the year that you are wanting to take the deductible to reduce cumulative tax liability.