Mo. Rev. Stat. § 300.155 — MO Code / Chapter 300 / Section 300.155
300.155 Traffic control signal legend — right turn on red light, when.
Status: in_force

300.155. Traffic control signal legend — right turn on red light, when. — Whenever traffic is controlled by traffic control signals exhibiting different colored lights, or colored lighted arrows, successively one at a time or in combination, only the colors green, red and yellow shall be used, except for special pedestrian signals carrying a word legend, and said lights shall indicate and apply to drivers of vehicles and pedestrians as follows:

(1) Green indication

(a) Vehicular traffic facing a circular green signal may proceed straight through or turn right or left unless a sign at such place prohibits either such turn. But vehicular traffic, including vehicles turning right or left, shall yield the right-of-way to other vehicles and to pedestrians lawfully within the intersection or an adjacent crosswalk at the time such signal is exhibited;

(b) Vehicular traffic facing a green arrow signal, shown alone or in combination with another indication, may cautiously enter the intersection only to make the movement indicated by such arrow, or such other movement as is permitted by other indications shown at the same time. Such vehicular traffic shall yield the right-of-way to pedestrians lawfully within an adjacent crosswalk and to other traffic lawfully using the intersection;

(c) Unless otherwise directed by a pedestrian control signal as provided in section 300.160 , pedestrians facing any green signal, except when the sole green signal is a turn arrow, may proceed across the roadway within any marked or unmarked crosswalk.

(2) Steady yellow indication

(a) Vehicular traffic facing a steady yellow signal is thereby warned that the related green movement is being terminated or that a red indication will be exhibited immediately thereafter when vehicular traffic shall not enter the intersection;

(b) Pedestrians facing a steady yellow signal, unless otherwise directed by a pedestrian control signal as provided in section 300.160 , are thereby advised that there is insufficient time to cross the roadway before a red indication is shown and no pedestrian shall then start to cross the roadway.

(3) Steady red indication

(a) Vehicular traffic facing a steady red signal alone shall stop before entering the crosswalk on the near side of the intersection or, if none, then before entering the intersection and shall remain standing until a green indication is shown except as provided in paragraph (b) of this subdivision;

(b) The driver of a vehicle which is stopped as close as practicable at the entrance to the crosswalk on the near side of the intersection or, if none, then at the entrance to the intersection in obedience to a red signal, may cautiously enter the intersection to make a right turn but shall yield the right-of-way to pedestrians and other traffic proceeding as directed by the signal at the intersection, except that the state highways and transportation commission with reference to an intersection involving a state highway, and local authorities with reference to an intersection involving other highways under their jurisdiction, may prohibit any such right turn against a red signal at any intersection where safety conditions so require, said prohibition shall be effective when a sign is erected at such intersection giving notice thereof;

(c) Unless otherwise directed by a pedestrian control signal as provided in section 300.160 , pedestrians facing a steady red signal alone shall not enter the roadway.

(4) In the event an official traffic control signal is erected and maintained at a place other than an intersection, the provisions of this section shall be applicable except as to those provisions which by their nature can have no application. Any stop required shall be made at a sign or marking on the pavement indicating where the stop shall be made, but in the absence of any such sign or marking the stop shall be made at the signal.

(L. 1965 p. 445 § 31, A.L. 1973 1st Ex. Sess. H.B. 26) Effective 2-28-74