Oregon Revised Statutes Oregon Vehicle Code § 811.065

(a) The driver of a motor vehicle may only pass a person operating a bicycle by driving to the left of the bicycle at a safe distance and returning to the lane of travel once the motor vehicle is safely clear of the overtaken bicycle. For the purposes of this paragraph, a “safe distance” means a distance that is sufficient to prevent contact with the person operating the bicycle if the person were to fall into the driver's lane of traffic. This paragraph does not apply to a driver operating a motor vehicle:

(b) The driver of a motor vehicle may drive to the left of the center of a roadway to pass a person operating a bicycle proceeding in the same direction only if the roadway to the left of the center is unobstructed for a sufficient distance to permit the driver to pass the person operating the bicycle safely and avoid interference with oncoming traffic. This paragraph does not authorize driving on the left side of the center of a roadway when prohibited under ORS 811.295, 811.300 or 811.310 to 811.325.

(c) The driver of a motor vehicle that passes a person operating a bicycle shall return to an authorized lane of traffic as soon as practicable.