Widening of the M25 between junctions 12 and 15 to dual-five lane, and provision of a new spur road to Heathrow Airport between junctions 14 and 15, connected to the M25 via a new free-flow junction. Six lanes each way will be provided between junctions 14 and 15.
As of April 2004, the Highways Agency has announced its intention to widen the rest of the M25 to at least dual four lane carriageways, except junctions 3 to 5.
This scheme was completed in and we're no longer accepting updates or changes to this page.
Work on junctions 12-15 is completed and the road opened fully to traffic.