SPEEDING: Is there a law against going too slow?

Yes, Ohio Revised Code 4511.22 specifies:

4511.22 Slow speed.

(A) No person shall stop or operate a vehicle, trackless trolley, or street car at such a slow speed as to impede or block the normal and reasonable movement of traffic, except when stopping or reduced speed is necessary for safe operation or to comply with law.

(B) Whenever the director of transportation or local authorities determine on the basis of an engineering and traffic investigation that slow speeds on any part of a controlled-access highway, expressway, or freeway consistently impede the normal and reasonable movement of traffic, the director or such local authority may declare a minimum speed limit below which no person shall operate a motor vehicle, trackless trolley, or street car except when necessary for safe operation or in compliance with law. No minimum speed limit established hereunder shall be less than thirty miles per hour, greater than fifty miles per hour, nor effective until the provisions of section 4511.21 of the Revised Code, relating to appropriate signs, have been fulfilled and local authorities have obtained the approval of the director.

(C) 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.