Couple of other suggestions.
1.Feed center rails of adjoining track sections through the bridge contacts, so they are dead when bridge is open. THis requires one additional contact at each end of the bridge. (I have a lift bridge that feeds a disconnected section of the layout, so only need this on one end.
2. Installing a microswitch pressed when the bridge comes down, permits wiring adjoining switch motors to route trains away from the bridge access tracks when bridge is up.
