The M4 eastbound has been closed since 4.30am this morning (Thursday) after a lorry hit a pedestrian.
Police closed all four lanes between junctions five (Langley, Staines) and 4B (M25), causing delays of 90 minutes.
Traffic is queued for five miles up to junction seven.
Why will the M4 reopen?
Highways England estimates the road will not be cleared until between 12am and 12.15am due to the seriousness of the incident.
They are advising drivers take an alternative route.
What alternative route can I take to the M25?
Follow the route marked by the hollow diamond diversion symbol on local road signs.
Leave the M4 at Junction 5. At the roundabout use the 3rd exit and join the A4 (London Road).
Continue on the A4 for approximately 2 miles, passing over the M25 to the junction with the A3044 (Stanwell Moor Road). Select the right turn lanes on approach to the Junction.
Turn right onto the A3044, and continue for approximately 2 miles to the A3113 roundabout. At the roundabout use the 3rd exit and join the A3113 Airport Way.
Continue to the M25 Jct 14 interchange (Poyle) roundabout. At the roundabout, use the 3rd exit and join the M25 Clockwise carriageway.
Continue to Jct 15 and using the nearside lanes, join the M25 Link road for the M4 Eastbound, Signed for Central London and Heathrow Airport. Rejoin the main M4 Eastbound carriageway.
It is worth noting that a collision on the M3 is also causing delays of around 15 minutes.
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