A. Whenever any roadway has been divided into two or more clearly marked lanes for traffic, the following requirements, in addition to all consistent requirements within the Motor Vehicle Code, shall apply:

(1)     a truck tractor shall be driven as nearly as practicable entirely within a single lane;

(2)     a truck tractor shall not be moved from the lane until the driver has first ascertained that the movement can be made with safety and then given a signal, not less than the last one hundred feet traveled by the truck tractor, of the driver’s intention to change lanes;

(3)     upon a roadway that is divided into three lanes, a truck tractor shall not be driven in the center lane except:

(a) when overtaking and passing another vehicle where the roadway is clearly visible and the center lane is clear of traffic within a safe distance;

(b) in preparation for a left turn; or

(c) where the center lane is at the time allocated exclusively to traffic moving in the direction the truck tractor is proceeding and is signposted to give notice of the allocation;

(4)     a truck tractor shall not be driven in the left lane of a roadway except when overtaking and passing another vehicle; provided, however, that this paragraph shall not prohibit driving in the left lane when traffic conditions, flow or road configuration, such as the potential of merging traffic, require the use of the left lane to maintain safe traffic conditions; and provided further that this paragraph shall not prohibit driving in the left lane of a roadway within the city limits of a municipality or upon a county road as long as such roadway is not part of the national system of interstate and defense highways;

and (5)     official signs may be erected directing slow-moving traffic to use a designated lane or designating those lanes to be used by traffic moving in a particular direction regardless of the center of the roadway, and drivers of vehicles shall obey the directions of every such sign.

B. A two-way left-turn lane is a lane near the center of the highway set aside for use by vehicles making left turns in both directions from or into the roadway. Two-way left- turn lanes shall be designated by distinctive roadway markings consisting of parallel double yellow lines, interior line dashed and exterior line solid, on each side of the lane. A vehicle shall not be driven in a designated two-way left-turn lane except when preparing for or making a left turn from or into a roadway. Vehicles turning left from the roadway shall not be driven in the two-way left-turn lane for more than two hundred feet while preparing for and making the turn. A vehicle turning left onto the roadway may utilize the two-way left-turn lane as a staging area by stopping and waiting for traffic proceeding in the same direction to clear before merging into the adjacent lanes of travel. A left turn shall not be made from any other lane where a two-way left-turn lane has been designated; provided, however, that this section shall not prohibit driving across a two-way left-turn lane when moving from a service drive onto such marked roadway.