The M48 is a 12-mile (19 km) long motorway in Great Britain, which connects Gloucestershire, England, and Monmouthshire, Wales, via the original Severn Bridge. The M48 is anomalously numbered, as it is entirely to the west of the M5 motorway thus falling into zone 5 of the motorway numbering system.[1][2] It is one of only three 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 then passes through a toll booth for westbound traffic only, and crosses the Severn and Wye rivers via their respective bridges. 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 most direct route for Chepstow and Caldicot.


Construction of the M48 near the hamlet of Ingst; at that time it was numbered M4

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]

After opening, the route became increasingly busy, and in 1984 a report was commissioned into a Second Severn Crossing.[5] After four years of construction this new route was opened in 1996 and the M4 was diverted over the newer bridge.[3] The original stretch of motorway was renumbered as M48 and now shares the traffic between England and Wales.


Junction 1 is the location of Severn View services (formerly called Aust Services when originally opened for the M4 motorway), which can also be accessed by the A403, from Avonmouth. There is a footpath leading from the service station 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. However, although the original building – which had offered views of the River Severn – was sold, due to business falling as a consequence of traffic using the newer bridge, operations continued in a new, much smaller development on an adjacent site nearer the motorway junction.[6]


M48 toll booths

Data from driver location signs are used to provide distance and carriageway identifier information.[7] Where a junction spans several hundred metres and start and end points are available, both are cited.

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
120.8 194.4 No tolls Tolls Toll booth
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
  •       Tolled

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. ^ "Aust / Severn View Services". Motorway Service Area Triva site. Archived from the original on 17 October 2004. Retrieved 18 April 2008. 
  7. ^ Traffic England Live Traffic Condition Map Archived 10 February 2012 at the Wayback Machine. Highways Agency – Locations extracted from Traffic Camera Popup identifier text

External links

Route map: Google

KML is from Wikidata