Section 811.370 - Failure to drive within lane; exception; penalty(1) Except as provided in subsection (2) of this section, a person commits the offense of failure to drive within a lane if the person is operating a vehicle upon a roadway that is divided into two or more clearly marked lanes for traffic and the driver does not: (a) Operate the vehicle as nearly as practicable entirely within a single lane; and(b) Refrain from moving from that lane until the driver has first made certain that the movement can be made with safety.(2) A person who operates a commercial motor vehicle within a multilane roundabout that is divided into two or more clearly marked lanes for traffic may operate the commercial motor vehicle in more than one lane when it is not practicable to remain entirely within one lane.(3) The offense described in this section, failure to drive within a lane, is a Class B traffic violation. 1983 c.338 §630; 2011 c. 85, § 2