A40 Traffic Update Today: Current traffic reports for the A40 today, July 20, 2026, indicate significant disruptions and delays across multiple regions due to roadworks and lane closures. Here is a detailed breakdown of the ongoing traffic disruptions, structural closures, and long-term project delays affecting major segments of the A40 today, July 20, 2026. Here’s everything you need to know about the A40 traffic update today, affected routes, alternative routes, and more.
A40 Traffic Update Today: Affected Routes in London
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High Holborn / Shaftesbury Avenue: Expect delays near the A40 High Holborn junction. Temporary signals are in operation due to emergency gas works, and St Giles High Street is completely closed. Drivers are advised to use alternative routes.
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A40 Westway: Two westbound lanes remain closed between the Marylebone Flyover and the Westway Roundabout for ongoing structural inspections. One westbound lane and all eastbound lanes are open, but heavy congestion is expected.
A40 Traffic Update Today: Affected Routes in Oxfordshire (Witney & Eynsham)
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Witney East: Expect delays between the B4022 (Witney East) and the Witney Town Centre/Ducklington turn-off. A lane closure is active in both directions for ongoing road layout modification works.
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Eynsham Roundabout: Delays are expected on the roundabout due to temporary traffic signals deployed for construction work.
A40 Traffic Update Today: Affected Routes in Gloucestershire & Monmouthshire Border
Leys Bend (Monmouth): While core remedial works have wrapped up, lane restrictions and final operations continue. The stretch of road is scheduled to fully reopen later this month.
A40 Traffic Update Today: Alternative Routes
To avoid the heavy traffic congestion on the A40 today, July 20, 2026, motorists are advised to use the following designated alternative and diversion routes depending on their region.
A40 Traffic Update Today: Alternative Routes in London
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Central London Utility Works: To bypass the emergency gas works gridlock at the High Holborn and Shaftesbury Avenue junction, use Theobalds Road or Clerkenwell Road to travel east-west across the city.
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Westway Flyover Delays: With westbound lane reductions active, commuters should bypass the Westway by utilizing the A5 (Edgware Road) or shifting south to the A4 (West Cromwell Road / Great West Road) to exit central London toward the M4/M25.
A40 Traffic Update Today: Alternative Routes in Oxfordshire
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Northern Bypass (Marston 30mph Zone): To avoid the eastbound utility cabling bottlenecks, exit early at the A44 (Oxford Western Bypass) or cut across the south of Oxford via the A34 and A4142 (Eastern By-Pass Road) to approach Headington from the south.
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Witney East / Shores Green: Long-distance drivers can completely bypass the A40 Witney lane closures by utilizing the A4095 through Long Hanborough or shifting north to the B4437 via Charlbury.
A40 Traffic Update Today: Alternative Routes in Wales
Pentrefelin to Llandeilo Full Closure: For the active dual-directional police incident closure, all light vehicles must divert using the A483 running north-south, or transition via the B4302 depending on your final direction of travel. Heavy goods vehicles (HGVs) should remain on the strategic M4 corridor to navigate around the rural closures entirely.
A40 Traffic Update Today: Helpline Numbers
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Phone: 0300 123 5000
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Phone: 0300 123 1213
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Phone: 0343 222 1234
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Phone: 01865 519800
The key takeaway for drivers on the A40 today, July 20, 2026, is that widespread disruptions require active route planning and the avoidance of known bottleneck zones.
