(1) Local transit authority bus shelters within the right-of-way of the state highway system may display and maintain commercial advertisements subject to applicable federal regulations, if any. Pursuant to RCW 47.12.120, the department may lease state right-of-way air space to local transit authorities for this purpose, unless there are significant safety concerns regarding the placement of certain advertisements.

(2) Advertisements posted on a local transit authority's bus shelter may not exceed twenty-four square feet on each side of the panel. Panels may not be placed on the roof of the shelter or on the forward side of the shelter facing oncoming traffic.