The M4 Thames Bridge Maidenhead is a motorway bridge between Dorney Reach, Buckinghamshire and Bray near Maidenhead, Berkshire in England built in the 1960s. The bridge carries the M4 Motorway across the River Thames, on the reach above Boveney Lock, and about 500 yards short of Bray Lock. It is one of three bridges carrying motorway traffic across the Thames, the others being the M25 Runnymede Bridge (just below Bell Weir Lock) and the M3 Chertsey Bridge.