See this Oregon Court of Appeals case, State v Rowe, Docket no. A128400. From the OJD Media Release page (use drop-down menu to get to the Ct of App):
“Defendant appeals his convictions for impeding traffic, ORS 811.130, and failure to obey a police officer, ORS 811.535. Defendant was standing next to his bicycle on a sidewalk in Portland when he refused a police officer’s order to “move along.” Held: To be convicted of impeding traffic, defendant had to have been “riding a bicycle.” To be convicted of failure to obey, the officer’s order had to have been lawful. On appeal, the state concedes that it failed to prove that defendant was riding a bicycle. Further, the state concedes that no other lawful basis existed for the officer to have ordered defendant to move. Reversed.”