35 ILCS 505/5.5
All carriers of motor fuel entering this State, and all carriers transporting motor fuel within this State, except railroads, pipe lines and water transportation companies operating as common carriers, and motor vehicles carrying not more than twenty gallons of motor fuel in the ordinary tank attached to such vehicle for use therein, shall carry a manifest showing the true name and address of the consignor and the consignee, the date and time of loading, the number of gallons and such other information as may be required by the Department. Every authorized agent of the Department shall have power to stop every such carrier for the purpose of examining such manifest, and to make any other reasonable investigation which will prevent avoidance of the tax provided for in this Act.
35 ILCS 505/5.5