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Factfile - Images - Timeline - Exit List
The M48 is basically what used to be the M4 across the first Severn Bridge. When the Second Severn Crossing was built, the M4 moved across there and the M48 took its place.
This little route does have two of its own junctions though: one in England for the A403, and one in Wales for Chepstow. When this road changed from M4 to M48, money was saved on new road signs by blanking out the first digit of the junction number - 21 becoming 1 and 22 becoming 2!
The M48 is actually wrongly numbered. Despite connecting to the M4 at each end, it lies north of the M4 and west of the M5, so it should really have a 5-number. If you want to get really technical, you could argue that since this is the old M4 route it remains the zone boundary, but I'm not convinced. This oddity is explored in considerable depth in CBRD's pages on Road Numbers.
Factfile
| Start | Olveston (M4) |
| Finish | Caldicot (M4) |
| Passes | Chepstow |
| Length | 12 miles |
| Terminates | None |
| Spurs | None |
| Meets | None |
Images
Views of the M48 from on and off the road. If you have a photo to contribute, contact me.
The Wye Bridge, often-overlooked neighbour of the Severn Bridge. It's just as impressive, with one large cable-stayed span. The Wye Bridge is the one that spans the England-Wales border, and the Severn Bridge is entirely in England.
Photo by Steven Jukes
From the banks of the river, the Severn Bridge looks deceptively short.
Photo by Steven Jukes
On the road, it's a different story - it goes on forever! (Especially when one lane is closed, as here).
Photo by Steven Jukes
Unlike the Second Severn Crossing, you can also walk and cycle across here. All that separates a fast moving motorway and a footpath is one line of steel cabling. You could quite easily step across!
Photo by Steven Jukes
Heading east from the bridges towards Bristol. Aside from these two magnificent engineering feats, the M48 is actually terribly dull.
Photo by Steven Jukes
Working on a maintenance project for the Severn Bridge, Alex was given a tour of the structure. Here's one of the formidable towers.
Photo by Alex
A little higher up, the size of the structure and its colossal support cables becomes clear.
Photo by Alex
The incredible view from the top, looking towards England.
Photo by Alex
The view in the other direction, showing the Wye Bridge, and beyond it, Wales.
Photo by Alex
Construction Timeline
When the various parts of the M48 were built, listed in chronological order.
| Open | Jct | Section |
|---|---|---|
| 1966 | Entire motorway | Severn and Wye Bridges (Opened as M4, became M48 in 1996) |
Exit List
All the junctions and destinations along the route.
| Junction | Eastbound | Westbound | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| (M4 J21) | London Bristol M4       |
M4 | EAST |
M4 | N/A |
|||||
2 miles, 2 lanes  |
 2 miles, 2 lanes |
|||||||||
| 1 | Severn Beach A403 Thornbury B4461  Severn View |
B4461 |
  |
A403 | Severn Beach A403 Thornbury B4461 Severn View |
|||||
| 3 miles, 2 lanes |
0 miles, 2 lanes |
|||||||||
 |
Severn Bridge Toll |
|||||||||
 Severn |
 |
Severn |
||||||||
| Wye |
|
Wye |
||||||||
| 3 miles, 2 lanes |
||||||||||
| 2 | Chepstow A466 (A48) |
A466 |   |
Chepstow A466 (A48) |
||||||
| 7 miles, 2 lanes |
7 miles, 2 lanes |
|||||||||
| (M4 J23) | N/A |
M4 |  WEST |
M4 | Newport Cardiff M4  |
With thanks to Meic Young for information on this page.
