(a) Notwithstanding an exemption provided in the federal safety regulations, other than an exemption relating to intracity or commercial zone operations provided in 49 C.F.R. Part 395, a rule adopted by the director under this chapter applies uniformly throughout this state.(b) A rule adopted under this chapter applies to a vehicle that requires a hazardous material placard.(c) A rule adopted under this chapter may not apply to a vehicle that is operated intrastate and that is:(1) a machine generally consisting of a mast, engine, draw works, and chassis permanently constructed or assembled to be used and used in oil or water well servicing or drilling;(2) a mobile crane that is an unladen, self-propelled vehicle constructed as a machine to raise, shift, or lower weight; or(3) a vehicle transporting seed cotton. Added by Acts 1997, 75th Leg., ch. 165, Sec. 30.151(a), eff. Sept. 1, 1997.Amended by: Acts 2005, 79th Leg., Ch. 247 (H.B. 749), Sec. 5, eff. September 1, 2005.