The motorway will be closed between junctions 1 and 3 between midnight and 5am so that signs can be installed to ensure drivers of Olympic buses maintain a 220 yard gap between each other as they travel over the Boston Manor Viaduct weight restriction zone west of junction 2.
While repair work is being carried out on the viaduct, a 7.5 tonne weight restriction is in place between junctions 3 and 2 in both directions. Olympic buses are exempt from the weight restriction eastbound but to maintain safety on the structure they must keep at least 220 yards apart.
Reflective bands will be installed on lighting columns, 200m apart, to give coach drivers a clear marker.
Traffic levels should be at their lowest during the closure but a clearly signed diversion will be in place with traffic diverted via the A4 and A312.
Passengers arriving late into Heathrow tonight will need to follow the diversion route and all road users from Berkshire heading in or out of London are advised to allow plenty of time for their journeys.
During the closure, repairs will also be carried out on two faulty surveilliance cameras.