The Severn Bridge (M48)
Route information
Maintained by Highways England and the South Wales Trunk Road Agency
Length13.0 mi (20.9 km)
Major junctions
East endAwkley

J21 → M4 motorway

J23 → M4 motorway
West endUndy
Road network
UK-Motorway-M45.svg M45UK-Motorway-M49.svg M49

The M48 is a 13-mile (21 km) long motorway in Great Britain, which crosses the Severn near Chepstow, Monmouthshire, linking England with Wales via the Severn Bridge. This road used to be the M4, and as a result is anomalously numbered: as it lies to the north of the M4 and to the west of the M5, it is in the Motorway Zone 5.[1][2] The M4, the M48 and the A48(M) motorway are the only motorways in Wales.


Travelling from east to west, after leaving the M4 at Awkley, junction 21, near Olveston in England, the M48 begins by heading north-west towards Aust, junction 1. It crosses the Severn and Wye rivers. Entering Wales, the M48 heads south-west after junction 2, passing to the south of Chepstow, past Crick and continuing in a south-westerly direction, passing Caldicot and Rogiet. The motorway rejoins the M4 at Undy, junction 23 to the east of Magor.

Junction 2 can be reached via the A466, which leads to the A48. The junction gives access to the Wye Valley, an Area of Outstanding Natural Beauty. When travelling either east or west on the M4, the M48 is the more direct route for Chepstow and Caldicot.


Construction near the hamlet of Ingst
Construction near the hamlet of Ingst
M48 toll boothstoll-free since 17 December 2018
M48 toll booths
toll-free since 17 December 2018

The M48 was opened as part of the M4 in 1966.[3] Before this date traffic between South West England and South Wales was either transported on a motorail service through the Severn Tunnel, used the Aust Ferry (which was unsuitable for large goods vehicles) or travelled through Gloucester to pass north of the Severn Estuary.[4] The route became increasingly busy and in 1984 a report was commissioned.[5] After four years of construction, the Second Severn Crossing was opened in 1996 and was designated M4.[3] The original stretch of motorway was designated M48 and continues to link England and Wales. Since 17 December 2018, both crossings have been toll-free.[6]


Severn View services are at junction 1, formerly called Aust Services when originally opened, and may also be accessed via the A403 from Avonmouth. There is a footpath leading from the services to allow pedestrians to cross the bridge. When the M4 was diverted over the Second Severn Crossing, it was anticipated that these services may close. The original building offered views of the River Severn. It was sold and operations continue in a new, smaller development on an adjacent site nearer the motorway junction.[7]


M48 motorway
mile km Eastbound exits (B carriageway) Junction Westbound exits (A carriageway)
117.6 189.3 London, Bristol M4 M4 J21
Chepstow, Services M48
Start of motorway
120.5 193.9 Avonmouth A403, Services J1
Avonmouth A403, Services
Severn Bridge
Entry into England

Wye Bridge
River Severn
River Wye
Severn Bridge
Entry into Wales
Wye Bridge
Chepstow A466 (A48)
Cas – gwent
J2 Chepstow A466 (A48)
Cas – gwent
130.2 209.6 Start of motorway
Chepstow, Services M48
Cas – gwent, Gwasanaethau
M4 J23
Newport, Cardiff M4
Casnewydd, Caerdydd
  • Distances in kilometres and carriageway identifiers are obtained from driver location signs/location marker posts. Where a junction spans several hundred metres and the data is available, both the start and finish values for the junction are shown.
1.000 mi = 1.609 km; 1.000 km = 0.621 mi

Data from driver location signs are used to provide distance and carriageway identifier information.[8] Where a junction spans several hundred metres and start and end points are available, both are cited. Information above gathered from Advanced Direction Signs May 2011.

See also


  1. ^ "Motorway Database – M48". CBRD. Retrieved 26 October 2007.
  2. ^ Steven Jukes. "Pathetic Motorways". Pathetic.org.uk. Retrieved 28 November 2012.
  3. ^ a b "Severn Crossing Dates". The Motorway Archive. Archived from the original on 13 November 2002. Retrieved 26 October 2007.
  4. ^ "Severn Crossing". The Motorway Archive. Archived from the original on 8 October 2007. Retrieved 26 October 2007.
  5. ^ "Second Severn Crossing". The Motorway Archive. Archived from the original on 7 February 2012. Retrieved 26 October 2007.
  6. ^ "Severn bridges: Final day of at least 800 years of tolls". BBC News. 16 December 2018. Retrieved 31 December 2018.
  7. ^ "Aust / Severn View Services". Motorway Service Area Triva site. Archived from the original on 17 October 2004. Retrieved 18 April 2008.
  8. ^ Traffic England Live Traffic Condition Map Archived 10 February 2012 at the Wayback Machine Highways Agency – Locations extracted from Traffic Camera Popup identifier text

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