A40 road
The A40 is a road which runs between London and Goodwick, in Wales. It is approximately long. The eastern section from Denham, Buckinghamshire to Wheatley, Oxfordshire is better served by the M40 and its former function of linking London with Cheltenham and Gloucester has been taken by the M4, A419 and A417 via Swindon.
In 1937, together with the A48 road, it formed parts of the London–Fishguard trunk road, as well as a part of the Newport–Shrewsbury trunk road. Much of the A40's length within England has been superseded by motorways, such as the M40, and has lost its trunk road status, though it retains the status west of Gloucester and its entirety within Wales.
History
18th century
Beaconsfield and Stokenchurch Turnpike
The road between Beaconsfield and Stokenchurch, that later became part of the A40, was put under the management of a turnpike trust by the ''''''20th century
The A40's 1923 route was from the City of London to Fishguard. The road still begins and ends in the same places, but a number of changes have been made to its route.On 1 April 1937, parts of the road and the A48 road was classed to form the London–Fishguard trunk road. Part of the road was also made part of the Newport–Shrewsbury trunk road.
The first change dates from 1935, between Ross-on-Wye and Abergavenny. The original route of the A40 was via Skenfrith, avoiding Monmouth; this road was renumbered the B4521. The A40 was rerouted via Raglan; between Ross and Raglan it replaced part of the A48, between Raglan and Llanvihangel-nigh-Usk it replaced the B4234, and between Llanvihangel and Abergavenny it replaced part of the A471.
Subsequently, the A40 was rerouted within west London. Western Avenue dates from the 1930s, but was originally opened as the A403. After the Second World War, the A40 was rerouted along part of the A219 and Western Avenue. The old route was renumbered the A4020.
Initially, the A40 went through the centre of Oxford, via Headington, Magdalen Bridge, the High Street, Carfax and Botley, and over the Swinford Toll Bridge to Eynsham. It was rerouted in the 1930s to follow the first section of the Oxford Ring Road to the north of the city, and then followed a direct line to bypass Eynsham. The old route became part of the A420 to Botley, and the section between Botley and Eynsham was renumbered the A4141, renumbered again in the 1960s to the B4044.
From the 1960s to 1990s a number of bypasses were built to divert the A40 around towns on the route, including Gloucester, Monmouth, Brecon, Carmarthen, St. Clears, Whitland.
In the mid-1980s a new dual carriageway was built for the A40 between Raglan and Abergavenny, and the 1935 route was renumbered the B4598.
Route
Central London – Denham
In central London it is High Holborn and then Oxford Street. At Marble Arch it joins the A5 Edgware Road as far as the Marylebone Flyover to become Westway then meets Western Avenue. For the greater part, this section is six lanes, otherwise four lanes. With two exceptions, Western Avenue forms a grade-separated motorway standard dual-carriageway between Paddington and the M40 motorway. The two at-grade intersections are Gypsy Corner and Savoy Circus; both of which are traffic light controlled. At Denham Roundabout, the six lane Western Avenue flows into the M40.Denham – Oxford
The A40 branches off the Denham roundabout to run as a dual carriageway. After the junction with the A413, the A40 follows the same route as the M40 as a single carriageway, passing through Beaconsfield and High Wycombe. Beyond Stokenchurch the road is much quieter; when meeting the B4009 and A329 those roads have priority. Approaching Oxford, the A40 becomes a busy dual carriageway, carrying traffic from the M40 to Oxford and beyond. The road forms the northern section of the Oxford Ring Road, crossing the A44 and the A34. In Oxford, it passes the Thornhill Park and Ride, where the OxfordTube, The Airline to Heathrow & Gatwick, & Oxford Park and Ride buses stop.Oxford – Cheltenham (M5)
The A40 passes under the A34, reverting to single carriageway for until the dual carriageway just east of Witney with a grade-separated junction. The dual carriageway finishes at a roundabout. For the rest of Oxfordshire and Gloucestershire until Cheltenham, other than for a few short stretches, the road is single carriageway. A height of above sea level is located west of the A429 junction. Before Andoversford the A436 breaks off to the west to try to take traffic away from descending into the centre of Cheltenham itself. The road travels through Cheltenham town centre along at least two parallel routes. Becoming a dual carriageway, it passes GCHQ in Cheltenham and the three-level stacked roundabout interchange with the M5 motorway. In February 2015, the Witney Oxford Transport Group proposed the reopening of Yarnton railway station as an alternative to improvements to the A40 road proposed by Oxfordshire County Council.Cheltenham (M5) – Abergavenny
The A40 is the Gloucester bypass, most of which is dual carriageway. The junction with the A48 to Chepstow is at Highnam. For the remainder of Gloucestershire, and a part of Herefordshire, the road is single carriageway until Ross-on-Wye. There it connects with the M50 motorway, and forms part of the high quality dual carriageway between South Wales and the English Midlands. From Ross-on-Wye to Monmouth the road follows the Wye Valley, an Area of Outstanding Natural Beauty, crossing the Wales–England border east of Monmouth. Just west of Monmouth are twin tunnels; these are the only tunnels on the A40. Near Raglan, the A40 has a grade separated junction with the A449. The A40 continues as a dual carriageway to Abergavenny.Abergavenny – M50 junctions
Abergavenny – Carmarthen
At Abergavenny is the A40 junction with the Heads of the Valleys road, and the A4042. Now the A465 becomes the primary route between the Midlands to the South Wales Valleys and Swansea; there is a dual-carriageway route to Carmarthen via the A465, M4 and A48.The A40 becomes single carriageway and continues through Abergavenny, following the north side of the Usk valley through the eastern part of the Brecon Beacons National Park until Brecon. At Bwlch between Abergavenny and Brecon, the A40 is above sea level. The A40 is dualed for over as it approaches a junction east of Brecon with the A470 north, which is the main north–south road through mid-Wales. Continuing as a dual carriageway, the A40 and A470 concurrent bypass Brecon to the south, crossing the River Usk here. At the western end of the bypass is a further junction with the A470 south. Beyond this point the A40 continues as a single carriageway, now south of the River Usk, and roughly follows the northern edge of the Brecon Beacons National Park. A height of above sea level is located less than east of Trecastle. In Llandovery the road crosses the Heart of Wales railway and the River Tywi; the road, railway and river then run parallel until Llandeilo, where the National Park ends and the railway turns south. The A40 continues west along the Tywi valley to Carmarthen where as a dual carriageway it forms the eastern bypass, meeting the terminus of the A48 at Pensarn. Here the A40 returns to being a primary route westwards.