Lewiston-Queenston Bridge, New York

The Lewiston-Queenston Bridge is the northernmost of three road bridges that pass over Niagara Gorge, one of  the most industrialized and scenic regions in the world. The bridge connects the US Interstate system with the most direct route to Toronto and Detroit. It has busy Ports of Entry on either side. It is the fourth busiest crossing on the US/Canada border, with delays of up to two hours, but at least there is a view. The international boundary is in the middle of the bridge, with a flag on either side.