ORS § 498.155
If a vehicle owner cited under ORS 498.154 to appear in a circuit or justice court upon an alleged parking offense fails to appear on or before the date and time stated on the citation, the court and the Department of Transportation may take such actions as are otherwise authorized by law under the Oregon Vehicle Code in the case of a failure to appear, except that in no case may a warrant of arrest be issued nor a criminal prosecution for failure to appear be commenced unless the citing or prosecuting authority, more than 10 days prior thereto, has sent a letter to the registered owner at the address shown upon the vehicle registration records of the department advising such owner of the charge pending and informing the owner that the owner may be subject to arrest if the owner does not appear in the court within 10 days to answer the charge. The letter must be sent by certified mail, restricted delivery, return receipt requested. A warrant of arrest may not be issued, nor a criminal prosecution for failure to appear be commenced if such a letter has not been sent or if the owner appears in court to answer the charge within 10 days after receiving the letter.
ORS 498.155