The department participates in the regulation of the movement of oversize and overweight vehicles and loads on the state highway system, in order to insure the safety of the traveling public, and to protect the integrity of the highways and the bridges. The department's responsibilities are accomplished through the authorization of the issuance of permits for the movement of oversize and overweight vehicles and loads by certain authorities, and the execution of special contracts for the movement of oversize and overweight vehicles and loads to travel across the width of a state highway. The sections under this chapter prescribe the policies and procedures for authorizing the issuance of permits and the execution of contracts.