RCW 46.61.125: Further limitations on driving to left of center of roadway.

(1) No vehicle shall be driven on the left side of the roadway under the following conditions: (a) When approaching or upon the crest of a grade or a curve in the highway where the driver's view is obstructed within such distance as to create a hazard in the event other traffic might approach from the opposite direction; (b) When approaching within one hundred feet of or traversing any intersection or railroad grade crossing; (c) When the view is obstructed upon approaching within one hundred feet of any bridge, viaduct or tunnel; (d) When a bicycle or pedestrian is within view of the driver and is approaching from the opposite direction, or is present, in the roadway, shoulder, or bicycle lane within a distance unsafe to the bicyclist or pedestrian due to the width or condition of the roadway, shoulder, or bicycle lane. (2) The foregoing limitations shall not apply upon a one-way roadway, nor under the conditions described in RCW 46.61.100 (1)(b), nor to the driver of a vehicle turning left into or from an alley, private road or driveway.