Oregon:ORS 811.370(a)(b)
- 811.370 Failure to drive within lane; penalty. (1) 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.
(Source: http://www.leg.state.or.us/ors/811.html)