Highways England have decided the road bridge on Woodlands Lane in Windlesham across the M3 is unsound and as such will be removed over the weekend of 18, 19, 20 & 21 November.
From 21:00 on the Friday, the M3 will fully close from the Lightwater junction through to the M25 until 05:30 on the Monday.
I believe official diversions will be for vehicles traveling towards London and North to go via Bracknell and pick up the M4, and for London bound vehicles traveling South to use the A331, then the Hogs Back and A3. Vehicles traveling from the London direction will use the M25 and then the M4 or A3 depending on their final destination.
Inevitably, some will end up going via Brookwood Crossroads, especially if they are relying on sat navs. Plan accordingly.