Oregon Revised Statutes Oregon Vehicle Code § 810.210

(a) All traffic control devices erected and used under this subsection shall conform to the state manual and specifications established under ORS 810.200.

(b) The commission has general supervision with respect to the placing, construction and operation of traffic control devices under this subsection for the purpose of obtaining, so far as practicable, uniformity as to type and location of traffic control devices throughout the state.

(c) Only the commission has authority over a state highway whether or not the state highway is within the jurisdiction of another road authority. No traffic control device shall be erected, maintained or operated upon any state highway under this subsection by any authority other than the commission, except with the written approval of the commission.

(d) When the governing body of a city makes a determination that placement or construction of a traffic control device on a highway within the city selected as a state highway under ORS 373.010 is necessary to carry out the provisions of the vehicle code or to regulate, warn or guide traffic, the city governing body shall submit written findings and recommendations to the Director of Transportation in support of placing or constructing the traffic control device on the state highway. If the director approves the findings and recommendations, the director shall notify the city governing body in writing and proceed to place or construct the traffic control device in accordance with the findings and recommendations. If the director does not notify the governing body of disapproval within 90 days after receipt of the findings and recommendations, the findings and recommendations shall be considered approved and the director shall proceed to place or construct the traffic control device in accordance with the findings and recommendations.

(e) The commission is authorized to classify, designate and mark both interstate and intrastate highways within the boundaries of this state.