(1) The legislative authority of any county, city, or town may erect, or permit the erection of, supplemental directional signs directing motorists to motorist service businesses qualified for motorist information sign panels pursuant to RCW 47.36.310 or 47.36.320 in any location on, or adjacent to, the right-of-way of any roads or streets within their jurisdiction.

(2) Appropriate fees may be charged to cover the cost of issuing permits, installation, or maintenance of such signs.

(3) Supplemental signs and their locations shall comply with all applicable provisions of this chapter, the Manual on Uniform Traffic Control Devices, and such rules as may be adopted by the department.