Simplify the following text for a Grade 12 native English-speaking person.
Original: The bridge carries part of the A3 road , which is maintained by the Greater London Authority ; the bridge itself is owned and maintained by Bridge House Estates ( see City Bridge Trust ) , an independent charity overseen by the City of London Corporation .
Simplified: The bridge carries part of the A3 road , which is maintained by the Greater London Authority ; the bridge itself is owned and maintained by a charity overseen by the City of London Corporation .