Oregon Revised Statutes Oregon Vehicle Code § 810.140

(1) Any road authority may designate lanes on its own highways that are to be used exclusively by buses or high occupancy-use passenger vehicles for the purpose of conserving energy and facilitating public transportation.

(2) Any restriction or limitation imposed under this section must be imposed by proper order. The restriction or limitation is effective when appropriate signs giving notice of the restriction or limitation are erected. A sign giving notice of a restriction or limitation shall be maintained in a conspicuous manner and shall be placed at each end of the highway or section of highway affected by the restriction or limitation and at such other places as necessary to inform the public.

(3) Penalties are provided under ORS 811.265 for failure to obey signs giving notice of any limitations or restrictions imposed under this section.