Bridge no. 060 on United States highway 77 in Marshall county is hereby designated as the SP4 Michael T. Martin memorial bridge. The secretary of transportation shall place suitable signs to indicate the bridge is the SP4 Michael T. Martin memorial bridge, 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.