Chicago, Ill., Mun. Code ch. 13-20 § 13-20-675

Every dynamic image display sign, including a city digital sign for which a permit application is submitted on or after April 2, 2014, shall comply with the following:


(a) Luminance .


(1) For signs located within a designated expressway corridor, the maximum luminance for any such sign shall not be greater than:


(A) 7,000 nits between 5 a.m. and sunset; and


(B) 300 nits between sunset and midnight.


(2) For all other signs not subject to subsection (a)(1), the maximum luminance for any such sign shall not be greater than:


(A) 7,000 nits between 5 a.m. and sunset; and


(B) 250 nits between sunset and midnight.


(3) No sign shall be illuminated between the hours of midnight and 5 a.m.; provided that an entity may keep its on-premise sign illuminated to no greater than 250 nits between the hours of midnight and 5 a.m., when the entity is open for business. For purposes of this subsection, "open for business" means an entity that is conducting its normal business or occupation and admits clients, customers or patrons during such time. This subsection shall not apply to any sign that is part of an emergency response network while such sign is displaying emergency information from any federal, state, or unit of local government.


(4) For purposes of this subsection, "designated expressway corridor" means any area within 660 feet of the nearest edge of the right-of-way of a designated expressway or toll road, as that term is defined in section 17-17-0244.5 .


(b) Dwell time . The text, image or display on the face of the sign shall not change more than once every 10 seconds. Twirl time shall not exceed 0.25 seconds.


(c) Motion .


(1) All motion is prohibited on the sign;


(2) During the message transition, the sign shall not display any visible effects, including but not limited to action, motion, fading, dissolving, blinking, or the illusion of such effects; and


(3) No message shall transition from one face to another face.


(d) Control/testing .


(1) All signs shall be equipped with an automatic dimmer control or other mechanism that automatically controls the sign's luminance in compliance with this section. In instances where the sign malfunctions, the sign shall either automatically shut off or turn to a black screen;


(2) Prior to the issuance of any permit for a sign, the applicant shall submit an affidavit that attests that the sign has been tested and complies with the dwell time, luminance, motion and other requirements of this section, and that the luminance intensity, motion and dwell time requirements are protected from manipulation by password-protected software or other method satisfactory to the commissioner, as set forth in rules and regulations; and


(3) The test of the luminance levels required by this section shall be made when the sign is set to full white.


(Added Coun. J. 4-30-14, p. 80382, § 3)