Speed limits for construction, school, and other zones

(a) The following maximum speed limit shall be in effect except where a special speed limit has been enacted: (1) Ten miles per hour below the posted speed limit within construction zones. (2) Twenty miles per hour. In any school zone, the beginning of which is demarcated by a school speed limit sign supplemented with a flashing speed limit sign beacon, and the end of which is demarcated by an end school zone or standard speed limit sign. (3) Twenty-five miles per hour. (A) When passing a school site or the grounds thereof, which are contiguous to or located in close proximity to, the highway and posted with the standard “school” warning sign while children are going to be leaving the school during opening or closing hours. This speed limit shall also apply during school recesses when passing any school grounds which are not separated from the highway by a fence or other physical barrier capable of restraining a child, while the grounds within seventy-five feet of the highway are in use by a child, and the highway is posted with the standard “school” warning sign. (B) During school days for a distance of up to one thousand feet on both sides of a crosswalk designated by the director of public works as a school crossing and posted with the standard “School Crossing.” (C) In a residential district, unless otherwise indicated. (D) On all highways and streets unless otherwise specified by this chapter. (4) Thirty miles per hour. In a business district. (b) Any person who violates any provision of section 24-149(a)(2), section 24- 149(a)(3)(A), or section 24-149(a)(3)(B) shall upon conviction be subject to fines equal to two times the fines as provided for in section 24-16.