Oregon Department of Transportation, Highway Division Rule Rule 734-020-0200 Yield Signs Attached to Transit Buses OAR 734-020-0200 (Yield Signs Attached to Transit Buses) through 734-020-0220 (Yield Sign Placement for Transit Buses) establish specifications for a yield sign to be attached to the back of transit buses as directed by ORS 811.167 (Failure to yield right of way to transit bus). The yield sign shall warn a person operating a vehicle approaching the rear of the transit bus that the person must yield when the transit bus in entering traffic.