Driving on roadways laned for traffic. Whenever any roadway has been divided into two or more clearly marked lanes for traffic

§ 3309.  Driving on roadways laned for traffic. Whenever any roadway has been divided into two or more clearly marked lanes for traffic the following rules in addition to all others not inconsistent therewith shall apply: (1)  Driving within single lane.-- A vehicle shall be driven as nearly as practicable entirely within a single lane and shall not be moved from the lane until the driver has first ascertained that the movement can be made with safety. (2)  Three lane roadways.-- Upon a roadway which is divided into three lanes and provides for two-way movement of traffic, a vehicle shall not be driven in the center lane except when overtaking and passing another vehicle traveling in the same direction when the center lane is clear of traffic within a safe distance, or in preparation for making a left turn, or where the center lane is allocated exclusively to traffic moving in the same direction that the vehicle is proceeding and the allocation is designated by official traffic-control devices. (3)  Lanes limited to specific use.-- Official traffic-control devices may be erected to restrict the use of specified lanes to specified classes or types of traffic or vehicles, including multioccupant vehicles or car pools, and drivers of vehicles shall obey the directions of every such device. (4)  Prohibitions against changing lanes.-- Official traffic-control devices may be installed prohibiting the changing of lanes on a section of roadway and drivers of vehicles shall obey the directions of every such device. Cross References. Section 3309 is referred to in sections 1603, 3326 of this title.