State highway 12 from its intersection with state highway 7, thence easterly on state highway 12 to the intersection of United States highway 56 and Interstate highway I-35, thence northeasterly on United States highway 56 to the Kansas-Missouri line is hereby designated “Shawnee Mission parkway.” The secretary of transportation shall place markers along the highway right-of-way at proper intervals to indicate that the route described is “Shawnee Mission parkway.” Each city through which Shawnee Mission parkway passes shall reimburse the secretary of transportation for the cost of placing such markers on such route in their city in such amount as each city is billed by the secretary.