For anyone travelling between Gatwick and Heathrow on the weekends of March 7 to 10 and March 21 to 24 there is a full closure of the M25 in both directions between Junctions 9 (Leatherhead) and 10 (Wisley) from 9pm on Friday to 6am on Monday May 13.
This follows similar closures last year for major roadworks.
Diversions will be on local roads, with delays expected.
Note that on the official diversion route the ULEZ (Ultra Low Emission Zone) cameras will be switched off. However drivers who try finding creative ways round using SatNav may be faced with ULEZ fines, as the cameras will not be switched off on other routes.
NOTE- This will affect the Oxford to Heathrow bus in both directions as most journeys extend to/start from Gatwick, and the drivers still need their statutory rest breaks (and vehicles out of position), so allow a lot of extra time for your journey or use the train instead.