(a) The commissioner of highways is hereby authorized to determine those portions of any highway where overtaking and passing or driving to the left of the roadway would be especially hazardous and may by appropriate signs or markings on the roadway indicate the beginning and end of such zones and when such signs or markings are in place and clearly visible to an ordinarily observant person every driver of a vehicle shall obey the directions thereof.
(b) Any person violating the provisions of this section is guilty of a misdemeanor and, upon conviction thereof, shall be fined not more than $100; upon a second conviction within one year thereafter, shall be fined not more than $200; and upon a third or subsequent conviction, shall be fined not more than $500.