Ohio's Right Lane Law...
4511.25 Lanes of travel upon
roadways of sufficient width.
(A) Upon all roadways of sufficient width, a vehicle or trackless trolley shall be driven upon the right half of the roadway, except as follows:
(1) When overtaking and passing another vehicle proceeding in the same direction, or when making a left turn under the rules governing such movements;
(2) When an obstruction exists making it necessary to drive to the left of the center of the highway; provided, any person so doing shall yield the right of way to all vehicles traveling in the proper direction upon the unobstructed portion of the highway within such distance as to constitute an immediate hazard;
(3) When driving upon a roadway divided into three or more marked lanes for traffic under the rules applicable thereon;
(4) When driving upon a roadway designated and posted with signs for one-way traffic;
(5) When otherwise directed by a police officer or traffic control device.
(1) Upon all roadways any vehicle or trackless trolley proceeding at less than the prevailing and lawful speed of traffic at the time and place and under the conditions then existing shall be driven in the right-hand lane then available for traffic, and far enough to the right to allow passing by faster vehicles if such passing is safe and reasonable, except under any of the following circumstances:
(a) When overtaking and passing another vehicle or trackless trolley proceeding in the same direction ;
(b) When preparing for a left turn;
(c) When the driver must necessarily drive in a lane other than the right-hand lane to continue on the driver's intended route.
(2) Nothing in division (B)(1) of this section requires a driver of a slower vehicle to compromise the driver's safety to allow overtaking by a faster vehicle.
(C) Upon any roadway having four or more lanes for moving traffic and providing for two-way movement of traffic, no vehicle or trackless trolley shall be driven to the left of the center line of the roadway, except when authorized by official traffic control devices designating certain lanes to the left of the center of the roadway for use by traffic not otherwise permitted to use the lanes, or except as permitted under division (A)(2) of this section.
This division shall not be construed as prohibiting the crossing of the center line in making a left turn into or from an alley, private road, or driveway.
(D) Except as otherwise provided in this division, whoever violates this section is guilty of a minor misdemeanor. If, within one year of the offense, the offender previously has been convicted of or pleaded guilty to one predicate motor vehicle or traffic offense, whoever violates this section is guilty of a misdemeanor of the fourth degree. If, within one year of the offense, the offender previously has been convicted of two or more predicate motor vehicle or traffic offenses, whoever violates this section is guilty of a misdemeanor of the third degree.