This page shows unplanned events on the M40 — collisions, broken-down vehicles, debris, emergency lane closures and anything else not scheduled in advance. Planned works are on the roadworks page instead.

What counts as an incident

National Highways logs an unplanned event when it affects the road: a crash, a vehicle stopped in a live lane, a spillage, an animal on the carriageway or a closure made at short notice. This list shows those reports for the whole M40, with the junctions and direction each one affects.

An incident report is often updated several times — lanes reopen, the expected clear time moves — and each card shows when it was last changed.

If you are caught up in one

• Follow the overhead signs. A red X over a lane means that lane is closed. The overhead signs page lists the messages being shown.
• If you break down, leave the carriageway if you can, get behind the barrier where it is safe, and call for help.
• Only use a mobile phone once you are safely stopped.

Reported collisions and the wider record

The Department for Transport records reported road collisions involving injury across Great Britain, including those on the M40. This page does not reproduce those statistics; it shows the incidents being reported now.

Where the most traffic passes

An incident has the widest effect where traffic is heaviest. In the Department for Transport road traffic statistics, 2025, the busiest M40 stretches were:

• Junction 1A to 2, M25 to Beaconsfield — 136,403 vehicles a day.
• Junction 2 to 3, Beaconsfield to High Wycombe — 133,167.
• Junction 14 to 15, Leamington to Warwick — 113,433.

For every stretch, see how busy the M40 is. For planned work, see M40 roadworks, and for the full list of reports, the latest M40 traffic news.

Traffic count figures on this page are from the Department for Transport road traffic statistics, 2025.