KRS 180.290

The department may, out of state highway funds, construct and maintain, either by itself or with any adjoining state, or any county or municipality of this or any adjoining state, or the United States government, or any two (2) or more of them, bridges across or tunnels under any boundary line stream of this state for the purpose of connecting any primary road of this state with a hard surface road or street in an adjoining state. In constructing bridges across or tunnels under any such boundary line stream, the department may locate the bridge or tunnel at any point it deems wise, but the bridge or tunnel shall not be located further than ten (10) miles from the terminus of the primary road intended to be reached by the bridge or tunnel. The department may construct any road necessary to connect a bridge or tunnel with the primary road intended to be served thereby.