Idaho Code § 40-1701

It is the intent of the legislature in amending this chapter to declare that it is necessary in the further promotion, regulation, control and administration of the secondary highways within the state of Idaho for the electorate to adopt a secondary highway system at the county level and for the elimination of impractical and uneconomical units and still maintain the element of home rule and administration of secondary highways within the various county and highway district systems exclusive of the state highway system.