The commission may administer and enforce all provisions of this chapter and inspect the vehicles, books, and documents of all motor carriers and the books, documents, and records of those using the service of the carriers for the purpose of discovering all discriminations and rebates and other information pertaining to the enforcement of this chapter and shall prosecute violations thereof. The commission shall employ auditors, inspectors, clerks, and assistants necessary for the enforcement of this chapter. The Washington state patrol shall perform all motor carrier safety inspections required by this chapter, including terminal safety audits, except for (1) those carriers subject to the economic regulation of the commission, or (2) a vehicle owned or operated by a carrier affiliated with a solid waste company subject to economic regulation by the commission. The Washington state patrol and the sheriffs of the counties shall make arrests and the county attorneys shall prosecute violations of this chapter.