Devon Expressway

The A38, parts of which are known as Devon Expressway, Bristol Road and Gloucester Road, is a major A-class trunk road in England.

The road runs from Bodmin in Cornwall to Mansfield in Nottinghamshire. It is long, making it the longest two digit A road in England. It was formerly known as the ''Leeds–Exeter Trunk Road'', when this description also included the A61. Before the opening of the M5 motorway in the 1960s and 1970s, the A38 formed the main "holiday route" from the Midlands to Somerset, Devon and Cornwall.

Considerable lengths of the road in the West Midlands closely follow Roman roads, including part of Icknield Street. Between Worcester and Birmingham the current A38 follows the line of a Saxon salt road.

For most of the length of the M5 motorway, the A38 road runs alongside it as a single carriageway road.

Route description

Bodmin to Birmingham

The road starts on the eastern side of Bodmin at a junction with the A30 before traversing the edge of the town to meet the A30 again. It travels through the picturesque Glynn Valley to Dobwalls and Liskeard, which are bypassed by a dual carriageway. The Dobwalls section contains a bat bridge. The A38 continues through the Cornish countryside, bypassing the centre of Saltash and continuing through the Saltash Tunnel. Immediately after the tunnel the River Tamar is crossed using the Tamar Bridge where the route resumes dual carriageway status. The section from Plymouth to Exeter is known locally as the Devon Expressway; it forms the southern border of Dartmoor National Park, and serves as a southward extension of the M5 motorway opening in 1977. It is long and was completed in the early 1970s. There are several grade separated junctions along its length mainly for local traffic; including a three-level stacked roundabout for the A386, which heads out towards Dartmoor National Park. The route was reserved for the Parkway as early as 1943, when it was included in the Plan for Plymouth.

In the early 1990s, the Marsh Mills junction was significantly remodelled, reducing the size of the roundabout and building a flyover over the top of it, allowing free flowing access from the Plympton bypass onto the Parkway. The viaducts carrying the A38 over the River Plym, which after the construction of the Marsh Mills flyover became the Exeter bound sliproads, were built in 1969–70 as part of the Plympton bypass. They were replaced in the 1990s due to suffering from Alkali Silica Reaction, and the project, completed in February 1996 at a cost of £12.25 million, involved the world's largest sideways bridge slide at the time for the , 5,500 tonne bridge. This required the road to be closed for only 48 hours, which won it an AA National Motoring Award in 1996 for innovation and minimisation of traffic congestion.

The road widens to a three-lane dual carriageway for the Plympton bypass. This opened in 1971 and was the first section of the Devon Expressway to be built on a new alignment, as well as being the first sizeable dual carriageway section of the route. Before Ivybridge, the route roughly parallels the original route, bypassing the village of Lee Mill which is now home to a large trading estate. The Ivybridge bypass opened in 1973 and the South Brent bypass in 1974, both on new alignments. The A38 passes Endsleigh Garden Centre, which used to have direct access from the dual carriageway, although since the early 2000s this has been closed and the garden centre is accessed from the Westover junction for Ivybridge. The route originally ended at the Marsh Mills roundabout, which when opened was the largest in Europe.

The section of the A38 between the A382 junction and Ashburton was built on a new alignment parallel to the old road, and was opened in 1974. Trago Mills, a locally well known retailer, is passed by the road. The Ashburton bypass, much like the Kennford bypass, uses the alignment of a much older 1930s single carriageway bypass, which was subsequently upgraded to dual carriageway by 1974. At the town of Buckfastleigh, the route once again bypasses on a new alignment, although due to the challenging topography of the area, the road crosses part of the town on a viaduct. The road occupies part of the alignment of the former Totnes to Ashburton railway line. From Buckfastleigh to the A385 junction, the current road follows the route of original single carriageway, with the majority of this section being upgraded between 1973 and 1974, although a small section at Dean Prior was upgraded between 1966 and 1967. This section is of a poor quality when compared to the majority of the route between Exeter and Plymouth, containing several side turnings with short exit/entry slips, and properties which back onto the road.

The town of Chudleigh and the village of Chudleigh Knighton are bypassed on a new alignment, which opened in 1973, and the following section at Heathfield up to the A382 junction was upgraded from the original route between 1966 and 1968. Some of this section follows part of the old Teign Valley Line railway.

Before Kennford, the route splits, with the A38 heading for Plymouth and the A380 heading towards Torbay. At this point, the road becomes a dual two-lane road although a third-lane emerges immediately for uphill traffic as the route climbs Haldon Hill, which has an average gradient of 1 in 20 over a 4 km distance, and a maximum gradient of around 1 in 10 (the adjacent A380 Telegraph Hill has about the same maximum gradient). The third lane is lost at the top of the hill, and the next section, the Harcombe bends is an original dual carriageway section, older than the rest of the route and this is evident with its sharp bends.

The Devon Expressway ends near the village of Kennford, south of Exeter, at the terminus of the M5. This initial section was opened in 1977, along with the remaining section of the M5, and is a three-lane dual carriageway. The village of Kennford is bypassed, on an alignment of a 1930s bypass, which was upgraded to a dual-carriageway in the 1960s and then widened to a dual three-lane road in 1975.

A junction to the south of Exeter represents a third meeting point of the A38 with the A30, from which point the A38 multiplexes with the M5 before re-emerging from junction 27 near Waterloo Cross, north of Exeter. From junction 27 the A38 heads north via Wellington, Taunton, Bridgwater, Highbridge and Bristol. From Waterloo Cross to Birmingham, the road is paralleled by the M5, where the A38 has reverted to taking local traffic only.

From Bristol, it continues north via Gloucester, Tewkesbury, Worcester and Bromsgrove to Birmingham. Between Worcester and Birmingham the A38 followed the line of an identified Saxon Salt road, one of six leading out of Droitwich. At Bromsgrove, it meets the M42 and the B4096 at junction 1 at Lickey End.

It passes through Upper Catshill and meets the M5 at junction 4 (along with the A491 road) near Lydiate Ash. From here to Edgbaston, the road is mostly dual carriageway, single-lane sections having been replaced in the first decade of the 21st century (see history section, below). Following completion of the Selly Oak bypass, the A38 deviates from its original route and briefly multiplexes with the A4040 outer Ring Road before forming the new bypass which is controversially named New Fosse Way. (The old route is designated B384 having been briefly B38).

In the centre of Birmingham, a section of the road becomes the Aston Expressway A38(M) motorway