Fixing America's Bridges Act This bill authorizes the Department of Transportation (DOT) to provide assistance to states to replace or rehabilitate certain bridges. Among other things, the bill authorizes DOT to provide assistance for certain activities on bridges, including painting, seismic retrofit, and installation of scour countermeasures (to prevent erosion of soil around a bridge foundation caused by flooding); includes a set-aside to ensure funding locally-owned bridges that are not on the federal-aid highway system; and provides for a federal cost-share of 90%.