(a) Other than a sign permitted as an electronic sign, a sign may not contain or be illuminated by flashing, intermittent, or moving lights, including any type of screen using animated or scrolling displays.
(b) A conforming sign may be illuminated but only by:
  (1) upward lighting of no more than 4 luminaires per direction of the sign face or faces of the structure; or
  (2) downward lighting of no more than 4 luminaires per direction of the sign face or faces of the structure.
(c) Lights that are a part of or illuminate a sign:
  (1) must be shielded, directed, and positioned to prevent beams or rays of light from being directed at any portion of the traveled ways of a regulated highway;
  (2) may not be of such intensity or brilliance as to cause vision impairment of a driver of any motor vehicle on a regulated highway or otherwise interfere with the driver's operation of a motor vehicle; and
  (3) may not obscure or interfere with the effectiveness of an official traffic sign, device, or signal.
(d) A temporary protrusion may not be illuminated by flashing or moving lights or enhanced by reflective material that creates the illusion of flashing or moving lights.
(e) Reflective paint or reflective disks may be used on a sign face only if the paint or disks do not:
  (1) create the illusion of flashing or moving lights; or
  (2) cause an undue distraction to the traveling public.
(f) A neon light may be used on a sign face only if:
  (1) the light does not flash;
  (2) the light does not cause an undue distraction to the traveling public; and
  (3) the permit for the sign specifies that the sign is an illuminated sign.
(g) This subchapter does not prohibit a temporary protrusion area of the sign face that displays only numerical characters and that satisfies this subsection and the requirements of §21.182 of this subchapter (relating to Commercial Sign Face Size and Positioning). An electronic sign may contain a temporary protrusion described by this subsection. The display on the temporary protrusion may be a digital or other electronic display, but if so:
  (1) it must consist of a stationary image;
  (2) it may not change more frequently than four times in any 24 hour period; and
  (3) the process of any change of display must be completed within two minutes.
(h) If the department finds that an electronic sign causes glare or otherwise impairs the vision of the driver of a motor vehicle or otherwise interferes with the operation of a motor vehicle, the owner of the sign, within 12 hours of a request by the department, shall reduce the intensity of the sign to a level acceptable to the department.

Source Note: The provisions of this §21.190 adopted to be effective July 1, 2011, 36 TexReg 2418; amended to be effective June 19, 2014, 39 TexReg 4668; amended to be effective March 14, 2018, 43 TexReg 1446