There is levied in Houston County, Alabama, for the purpose of constructing and maintaining public roads, streets, bridges, and ferries, a privilege tax of not more than one cent per gallon on all gasoline or gasohol which is sold or delivered in the county, for the privilege of selling or delivering same. For purposes of this part, the tax herein applies only to gasoline and gasohol; any other motor vehicle fuel or oil or gas is expressly exempt from the application of this part.