thdivision of the United States army highway. United States highway 24 from the west city limits of Topeka, then west on United States highway 24 to the west junction of United States highway 24 and K-177 highway, then south to the junction of K-177 highway and K-18 highway, then west on K-18 highway to the western city limits of the city of Manhattan, is hereby designated as the 75th division of the United States army highway. The secretary of transportation shall place signs along the highway right-of-way at proper intervals to indicate that the highway is the 75th division of the United States army highway, 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 and an additional 50% of the initial cost to defray future maintenance or replacement costs of such signs. The secretary of transportation may accept and administer gifts and donations to aid in obtaining and installing suitable signs.