A person commits the offense of passing in a no passing zone if the person drives a vehicle on the left side of a roadway in a no passing zone that has been established and designated to prohibit such movements by appropriate signs or markings posted on the roadway.
The provisions of this section do not apply under any of the following circumstances:
When a driver turns left into or from an alley, intersection, private road or driveway.
When an obstruction or condition exists making it necessary to drive to the left of the center of the roadway provided that a driver doing so shall yield the right of way to all vehicles traveling in the proper direction upon the unobstructed portion of the roadway within a distance that would constitute an immediate hazard.
The offense described in this section, passing in a no passing zone, is a Class B traffic violation. [1983 c.338 §639; 1985 c.16 §316]