Upon the conclusion of a driver improvement interview, the department's referee shall make findings on the matter under consideration and shall notify the person involved in writing by personal service of the findings. The referee's findings shall be final unless the person involved is notified to the contrary by personal service or by certified mail within fifteen days. The decision is effective upon notice. The person upon receiving such notice may, in writing and within ten days, request a formal hearing.

Persons not entitled to formal hearing: RCW 46.20.324.