as an agreement to waive a license revocation, which the DOT could otherwise seek, in return for Schumacher’s guilty plea. However we view the plea agreement here, the county attorney had no authority to do what he did. We note at the outset that the county attorney does not have any independent authority to issue declaratory rulings on the applicability of the revocation provisions of chapter 321 or to adjudicate the rights of license holders under chapter 321. The DOT is, in the first instance, charged with the responsibility to interpret and enforce the motor vehicle laws governing the revocation of drivers’ licenses. Iowa Code § 321.2 (1993) (“The state department of transp independent of the criminal sanctions of chapter 124. Iowa DistCt. for Buchanan County, 504 N.W.2d at 898 (<HOLDING>); Heidemann, 375 N.W.2d at 668 (“license
holding that the standard of proof in revocation proceedings is a preponderance of the evidence holding that collateral estoppel does not require a criminal court to accept as binding an administrative proceedings license revocation determination holding that probation revocation proceedings are clearly not criminal proceedings recognizing the clear separation between criminal proceedings involving operatingwhileintoxicated prosecutions and administrative proceedings such as the revocation of a motor vehicle license recognizing right of allocution in probation revocation proceedings