Drive on right side of roadway; exceptions.

A. Upon all roadways of sufficient width a vehicle shall be driven upon the right half of the roadway, and where practicable, entirely to the right of the center thereof, except as follows: (1) when overtaking and passing another vehicle proceeding in the same direction under the rules governing such movement; (2) when the right half of a roadway is closed to traffic while under construction or repair; (3) upon a roadway divided into three marked lanes for traffic under the rules applicable thereon; or (4) upon a roadway designated and signposted for one-way traffic. B. Upon all roadways any vehicle proceeding at less than the normal 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, or as close as practicable to the right-hand curb or edge of the roadway, except when overtaking and passing another car proceeding in the same direction or when preparing for a left turn at an intersection or into a private road or driveway.