Whenever any roadway has been divided into 2 or more clearly marked lanes for traffic, the following rules in addition to all others consistent herewith shall apply:
(1) A vehicle shall be driven as nearly as practicable entirely within a single lane and shall not be moved from such lane until the driver has first ascertained that such movement can be made with safety.
(2) Upon a roadway which is divided into 3 lanes for 2-way traffic, a vehicle shall not be driven in the center lane except when overtaking and passing another vehicle where the roadway is clearly visible and such center lane is clear of oncoming traffic within a safe distance, or in preparation for a left turn or where such center lane is at the time allocated exclusively by traffic-control devices to traffic moving in the direction the vehicle is proceeding.
(3) Traffic-control devices may be erected directing specified 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 traffic-control device.
(4) Traffic-control devices may be installed prohibiting the changing of lanes on sections of roadway and drivers of vehicles shall obey the directions of every such device.
Structure Delaware Code
Subchapter III. Driving on Right Side of Roadway; Overtaking and Passing, etc.
§ 4114. Driving on right side of roadway; exceptions.
§ 4115. Passing vehicles proceeding in opposite directions.
§ 4116. Overtaking a vehicle or bicycle on the left.
§ 4117. When overtaking on the right is permitted.
§ 4118. Limitations on overtaking on the left.
§ 4119. Further limitations on driving to left of center of roadway.
§ 4120. No-passing zones; exceptions.
§ 4121. One-way roadways and rotary traffic islands.
§ 4122. Driving on roadways laned for traffic.
§ 4123. Following too closely.