What factors must be considered when setting speed limits

(a) The department of transportation or a county shall consider the following factors when setting a maximum speed limit pursuant to section 291C-102: (1) An engineering study conducted for the road whose maximum speed limit is being set, which shall include an analysis of the current speed distribution of free-flowing vehicles; provided that this paragraph shall not apply when the department of transportation or any county reduces a maximum speed limit within: (A) One mile of a school; and (B) Ten miles per hour of the current speed limit for that road; (2) For sections of highways with residential or commercial areas or schools immediately adjacent to the roadway, the department of transportation or a county shall, to the extent practicable, consider guidance provided by the National Association of City Transportation Officials; provided that nothing in this paragraph shall be construed to supersede any applicable federal standards or requirements; and (3) Any other factors prescribed by the Federal Highway Administration's Manual on Uniform Traffic Control Devices, as amended. (b) As used in this section, "engineering study" means a survey of highway and traffic conditions in accordance with methods determined by the department of transportation for use by state and local authorities. An engineering study shall consider the following factors: (1) Roadway characteristics including but not limited to shoulder condition grade, alignment, sight distance, and lane widths; (2) Roadside development and environment, including the following: (A) Number and types of side road access including signalized or unsignalized intersections; (B) Pedestrian activity and facilities; (C) Parking practices and activity; and (D) Type of bicycle accommodations and facilities; (3) Motor vehicle crashes resulting in deaths or injuries; and (4) Prevailing speeds as determined by traffic engineering measurements.