OAR 740-100-0220
OAR 740-100-0220. Extra Vehicles Operating on Schedule
When two or more passenger-carrying vehicles are operated on an established schedule, and the leading vehicle or vehicles are loaded to capacity:
(1) A suitable sign must be displayed on each leading vehicle or vehicles indicating that another vehicle is following; or
(2) The driver of such leading vehicle or vehicles must clearly indicate to waiting patrons that another vehicle is following.