Wash. Admin. Code § 204-32-010
(2) "Private carrier bus" means every motor vehicle designed for the purpose of carrying passengers used regularly to transport persons in furtherance of any organized agricultural, religious, or charitable purpose, and having a seating capacity for:
(b) Fifteen passengers if the transportation is provided not for compensation.
Such term does not include buses operated by common carriers under a franchise granted by any city or town or the Washington public utilities commission.
[Statutory Authority: RCW 46.37.005 and 46.37.290. WSR 14-03-017, § 204-32-010, filed 1/7/14, effective 2/7/14; WSR 08-19-078, § 204-32-010, filed 9/16/08, effective 10/17/08; Order 7001, § 204-32-010, filed 6/10/70, effective 7/15/70.]