(a) The portion of United States highway No. 40 traversing this state where it crosses the Missouri-Kansas border on the east to the point where it leaves the state on the west at the Kansas-Colorado line, be and it is hereby designated as the official east-west Blue Star memorial highway in the state of Kansas.

(b) If the state of Missouri designates a portion of interstate highway 70 as the Truman/Eisenhower Presidential highway, or something substantially similar, then the portion of United States highway No. 40 from where it crosses the Missouri-Kansas border, to the west city limits of Topeka, and then from the junction of highway K-15 with United States highway No. 40, then west on United States highway No. 40 to the point where it leaves the state at the Kansas-Colorado line, shall be designated as the official east-west Blue Star memorial highway in the state of Kansas.