(a) The secretary of transportation may determine and declare:

(1) Based on an engineering and traffic investigation that an existing speed limit is greater or less than what is reasonable or safe under the conditions found to exist at any intersection or other place or upon any part of the state highway system, or upon any city street which is a state highway connecting link; or

(2) based on information or circumstances known to the secretary, without an engineering or traffic investigation, that a speed less than the maximum otherwise allowed is warranted. If the secretary determines to designate a speed limit under authority of this paragraph the secretary shall prepare a statement and notice of alteration of maximum speed limit. The statement shall be in writing, shall specify the designated maximum speed limit, the route or routes affected, or any segment thereof, the factors upon which the decision is based and the date on which the speed limit shall be effective. The notice shall specify the route or routes affected, or segments thereof, the designated maximum speed limit and the effective date. The notice required under this paragraph shall be sent to the Kansas highway patrol and the sheriff of any county in which the affected route or routes are located prior to the effective date of the new maximum speed limit.

(b) Any maximum speed limit declared under subsection (a) may be effective at all times or at designated times; and differing speed limits may be established for different times of day, different types of vehicles, varying weather conditions, or other factors bearing on safe speeds. In addition to any other requirement imposed on the secretary of transportation, no alteration in the speed limits under subsection (a) shall be effective until posted upon appropriate fixed or variable signs.

(c) The secretary of transportation may establish the speed limit within a road construction zone, as defined in Kan. Stat. Ann. § 8-1458a, and amendments thereto, upon any highway under the jurisdiction of the secretary, and the speed limit shall be effective when appropriate signs giving notice thereof are erected.

(d) The secretary of transportation shall not establish any maximum speed limit in excess of the maximum speed limits established by Kan. Stat. Ann. § 8-1558, and amendments thereto, except that the secretary may establish a speed limit which exceeds the limit established under Kan. Stat. Ann. § 8-1558(a)(4), and amendments thereto, by five miles per hour on any such highway located outside of an urban district. Prior to increasing any speed limit authorized pursuant to this subsection, the secretary shall consider the effects of Kan. Stat. Ann. §§ 8-1560c and 8-1560d before establishing a higher speed limit.

(e) The secretary of transportation shall not alter any speed limit established under Kan. Stat. Ann. § 8-1560(a)(4), and amendments thereto, without first obtaining approval from the local authority.