Tex. Transp. Code § 545.051
(a) An operator on a roadway of sufficient width shall drive on the right half of the roadway, unless:
(2) an obstruction necessitates moving the vehicle left of the center of the roadway and the operator yields the right-of-way to a vehicle that:
(b) An operator of a vehicle on a roadway moving more slowly than the normal speed of other vehicles at the time and place under the existing conditions shall drive in the right-hand lane available for vehicles, or as close as practicable to the right-hand curb or edge of the roadway, unless the operator is:
(c) An operator on a roadway having four or more lanes for moving vehicles and providing for two-way movement of vehicles may not drive left of the center line of the roadway except:
Acts 1995, 74th Leg., ch. 165, Sec. 1, eff. Sept. 1, 1995.