Whenever any roadway has been divided into two or more clearly marked lanes for traffic, the following rules, in addition to all others consistent herewith, shall apply.
(A) The driver of a vehicle shall drive as nearly as practical entirely within a single lane and shall not move from the lane until the driver has first ascertained that the movement can be made with safety.
(B) 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 direction of every sign.
(1998 Code, § 118-39) Penalty, see § 71.99