Building bridges over navigable streams; determination of amount of bonds required.

Whenever a majority of the members of any board of county commissioners, in either of the counties of the state, shall vote to acquire any property, or right, or to double-deck, or parallel, or build any bridge, authorized in the transportation code; or when a petition signed by 10 percent of the duly qualified electors of any county is presented to the board of county commissioners of such county and praying any bridge be acquired, or double-decked or built, authorized by the transportation code, then such board of county commissioners shall immediately employ thoroughly competent and reliable experts who shall perform such service and give such information as required and shall be paid for such service out of the general revenue fund of such county; and such board of county commissioners shall then promptly determine the amount of county bonds required for such purposes, the rate of interest to be paid thereon, and the time when the principal and interest of such bonds shall become due and where payable.