No person shall open the door of a motor vehicle on the side available to moving traffic unless and until it is reasonably safe to do so, nor shall any person leave a door open on the side of a motor vehicle available to moving traffic for a period of time longer than necessary to load or unload passengers.
Mo. Rev. Stat. § 300.340
Opening and closing vehicle doors
Effective: 28 Aug 1965; (L. 1965 p. 445 § 69)
Official source: Missouri Revisor of Statutes. Reproduced from public-domain Missouri statutes; confirm against the official source for the current text. Not legal advice.