[The portion of highway K-99] from the south city limits of Frankfort, south on K-99 highway to the junction of K-99 and interstate highway 70, is hereby designated as “The road to Oz.” The secretary of transportation shall place signs along the highway right-of-way at proper intervals to indicate that the highway is “The road to Oz,” except that such signs shall not be placed until the secretary has received sufficient moneys from gifts and donations to reimburse the secretary for the cost of placing such signs. The secretary of transportation may accept and administer gifts and donations to aid in obtaining and installing suitable signs.