(a) All state routes are hereby designated as through highways, provided that stop signs, yield signs or traffic-control signals shall be erected at all intersections with such through highways by the Department of Transportation as to highways under its jurisdiction and by local authorities as to highways under their jurisdiction, except as otherwise provided in this section. Where two or more state routes that are through highways intersect, and no traffic-control signal is in operation, stop signs or yield signs shall be erected at one or more entrances thereto by the Department or by local authorities having jurisdiction, except as otherwise provided in this section. Whenever the Director of Transportation determines on the basis of an engineering and traffic investigation that stop signs are necessary to stop traffic on a through highway for safe and efficient operation, nothing in this section shall be construed to prevent the installations. When circumstances warrant, the Director also may omit stop signs on roadways intersecting through highways under his or her jurisdiction. Before the Director either installs or removes a stop sign under this division, he or she shall give notice, in writing, of that proposed action to the affected local authority at least 30 days before installing or removing the stop sign.
(b) Other streets or highways, or portions thereof, are hereby designated as through highways if they are within the municipality, if they have a continuous length of more than one mile between the limits of the street or highway or portion thereof, and if they have stop or yield signs or traffic-control signals at the entrances of the majority of intersecting streets or highways. For purposes of this section, the limits of the street or highway, or portion thereof, shall be the municipal corporation line, the physical terminus of the street or highway, or any point on the streets or highway at which vehicular traffic thereon is required by regulatory signs to stop or yield to traffic on the intersecting street, provided, that in residence districts, the municipality may by ordinance designate the street or highway, or portion thereof, not to be a through highway and thereafter the affected residence district shall be indicated by official traffic-control devices. Where two or more through highways designated under this division intersect and no traffic-control signal is in operation, stop signs or yield signs shall be erected at one or more entrances thereto by the Department or by local authorities having jurisdiction, except as otherwise provided in this section.
(c) The Department or local authorities having jurisdiction need not erect stop signs at intersections they find to be so constructed as to permit traffic to safely enter a through highway without coming to a stop. Signs shall be erected at the intersections indicating that the operator of a vehicle shall yield the right-of-way to or merge with all traffic proceeding on the through highway.
(d) Local authorities, with reference to highways under their jurisdiction, may designate additional through highways, and shall erect stop signs, yield signs or traffic-control signals at all streets and highways intersecting the through highways, or may designate any intersection as a stop or yield intersection, and shall erect like signs at one or more entrances to the intersection.
(R.C. § 4511.65)