This page lists messages from the signs National Highways publishes, which is not every sign on the road. Each one is shown with where on the M40 it stands.

What the signs are for

National Highways uses message signs to warn drivers of what lies ahead — a closed lane, queues after a junction, a closure later tonight, or a general safety message. Checking the published ones here before you set off can flag a problem on your route in good time.

Common messages and what they mean

• Lane closed ahead — move over in good time; there is an obstruction or works.
• Queue ahead — slow traffic after the next junction; expect to brake.
• Closed at night or a date — advance notice of a planned closure. The closures tonight page has the detail.
• A red X — the lane underneath is closed; do not drive in it.

Where on the M40 you will see them

Signs sit along the length of the motorway, with more of them near the busiest junctions. On the approach to the M42 at the northern end of the M40, Active Traffic Management is used, so the gantries there can set lane use and speed as well as show messages.

Signs before the big junctions

The messages matter most on the approach to the junctions where the M40 meets another major road, because that is where drivers can still change route:

• Junction 1A, for the M25.
• Junction 4, the A404 for Marlow, Maidenhead and the M4.
• Junction 8, the A40 for Oxford and Cheltenham.
• Junction 9, the A34 for Newbury and the A41 for Bicester.
• Junction 10, the A43 for Northampton and Milton Keynes.
• Junction 15, the A46 for Coventry and Stratford-upon-Avon.

Each entry here shows the sign’s location, the text displayed and when it was last set. Signs can change quickly, so treat the list as a guide to the moment it was refreshed.

For speed limits set by the signs, see M40 speed limits now. For the reports behind the messages, see the latest M40 traffic news.