(a) The commission shall adopt a manual and specifications of uniform standards for traffic control devices consistent with the provisions of the vehicle code for use upon highways in this state.
(b) The commission is authorized to provide a uniform system of marking and signing highways within the boundaries of this state.
(c) The commission is authorized to determine the character or type of traffic control devices to be used in this state.
(2) The authority granted under this section is subject to all of the following:
(a) The system of marking and signing established under this section shall correlate with and, as far as possible, conform to the system adopted in other states. The commission may include in the system signs and signals that show internationally recognized and approved symbols.
(b) So far as practicable, all traffic control devices in this state shall be uniform as to type and location.
(c) All traffic control devices placed or operated in this state shall conform to specifications approved by the commission.
(d) Stop signs and yield signs shall be illuminated at night or so placed as to be illuminated by the headlights of approaching vehicles or by street lights. [1983 c.338 §164; 1985 c.16 §53; 1993 c.522 §2]