The A40 is one of the major A roads in the UK, serving as a route from the centre of the country’s capital, London, to Wales. It actually concludes in the Welsh town of Fishguard, in Pembrokeshire, and is therefore still informally known by some as the London to Fishguard road instead of the A40. Spanning a total distance of some 263 miles, it’s the seventh longest road in the UK.
The starting point of the A40 is near the Edgware Road and Paddington Green area in central London. It moves west out of the city, passing several London boroughs, including Westminster, Kensington and Chelsea, Hammersmith & Fulham, and Ealing. It crosses the north circular road and runs past Northolt and Uxbridge before it flows into the M40 at the Denham Roundabout. Here, motorists can join the M40 and also gain access to the M25.
The M40 takes over as the major route at that point but when that continues north, towards Banbury and then into the west Midlands, bringing motorists to Warwick and the outer fringes of Birmingham, the A40 gains prominence again. From the outskirts of Oxford, it runs through the picturesque Cotswolds, navigates around Cheltenham, past Gloucester, Ross-on-Wye and then deep into Wales. It touches on the edge of the Brecon Beacons, before going past Carmarthen, Haverfordwest and then into Pembrokeshire.
The route must be one of the most varied A roads in the UK, when driven in its entirety, considering the contrast between the hectic of the City of London, and the scenic views and almost mountain-like conditions in the west of the country and into Wales.
Worst Junctions on the A40
As one of the main trunk roads linking London with Wales, passing through the west of the UK, you should certainly expect some heavy traffic in places - especially if your drive starts in the capital. Before setting off on your journey, check the RAC Route Planner for latest traffic news and awareness of any incidents or accidents on the A40 that may cause delays. These, however, are usually busy junctions.
Golden Valley Junction - also known as the Golden Valley Interchange, this is where the A40 meets junction 11 of the M5, in Gloucestershire. It’s one of the busiest junctions on the route.
Headington Roundabout - queues are always highly likely here, which is shortly after the M40 runs north, and just outside Oxford.
Wye Bridge - this junction, in Monmouth, gets notoriously busy, suffering traffic congestion and poor vehicle flow. Here, the A40 meets the A449, which takes traffic towards Newport.
Over roundabout - this is a particularly busy junction for commuters heading into Gloucester. It was subject to a £2m improvement scheme in 2018.
Accident Hotspots on the A40
The A40 carries thousands of vehicles and motorists every day and so, sadly, accidents are inevitable from time to time. Accidents can occur at any time, so drivers should always be alert and vigilant, and stay up to date with A40 traffic updates to be aware of incidents that may just have occurred. However, on the A40, as with many other major roads, there are sections that have a reputation for being accident hotspots. Take extra care if you’re driving on such parts of the A40.
The stretch of the A40 in Wales between Carmarthen and Llandovery was once known as one of Britain’s most dangerous roads after a spate of fatal and serious accidents. It’s a section of the A40 which is single carriageway.
Another section of the A40 that has a reputation as an accident hotspot is around the Cheltenham and Gloucester area.
Upcoming A40 Major Roadworks
Travelling on the A40? However long your journey, and regardless of which section of the route you’re driving on, it’s always best to check for any roadworks before you get behind the wheel. Use the RAC’s route planner to get a live picture of traffic delays and incidents that might affect your journey.
In 2018, there were extensive roadworks to help improve traffic flow, and ease congestion, around the A40 Over Roundabout in Gloucestershire. This caused significant queuing at the time of operation, but the project was completed in September.
Other planned major roadworks in the A40 include:
A40 London Road - a £6.6m investment to improve junctions and pedestrian crossings, and upgrade in technology, in the stretch of road from Abbey Way to the M40 junction at Loudwater, is planned.