Devon The road starts in Ilfracombe as part of the town's High Street, and is mostly single carriageway. The road passes through the villages of Knowle and Braunton, before becoming
dual carriageway standard at Ashford, which continues for the short distance to Barnstaple. From there it passes the town's railway station then merges with the
A39 for a short while before splitting back off near Portmore Golf Park. The section from Barnstaple to the M5 near Tiverton has been designated the North Devon Link Road, and enables relatively fast access to the
Atlantic Highway, relieving pressure on the northern section of the A39 and A358. This section is a modern, wide single carriageway
trunk road (which was de-trunked in 2002), apart from the stretch between Tiverton and the M5, which is dual carriageway.
Tiverton Parkway railway station is situated close to the junction with the motorway in order to give easy rail connections for people driving from north Devon. Some sections of road are on the alignment of the
Devon and Somerset Railway, including the Castle Hill Viaduct over the River Bray, where the stone pillars formerly used to support a lattice girder railway bridge now support the road.
Somerset and south Wiltshire The road merges with the
A38 from Junction 27 of the
M5 until
Taunton. The rest of the road, from there to Swindon, is largely county-road class. It crosses the
Somerset Levels separating
Curry Moor from North Moor and Salt Moor, where in flood conditions such as the winter of 2012/2013 the Athelney spillway runs across the road if the drain level at Curry Moor pumping station exceeds 7.1m, making the road impassable. Next, it passes by the towns of Street and Glastonbury and briefly merges with the
A39 again. From there it continues northeast near
Cranmore (the home of the
East Somerset Railway) and originally passed through
Frome, which it now bypasses to the east. It briefly merges with the
A36 then passes through villages at
Rode and into Wiltshire at
Southwick. Here it is signposted alternatively via
Trowbridge or through
North Bradley and
Yarnbrook (which could have been reached if the Frome bypass had continued to follow the railway) to merge with the
A350 before diverging towards
Devizes.
A4361 From its junction with the
A4 at Beckhampton, northwards through
Avebury, the A361 has been renumbered the
A4361 as it heads for
Swindon town centre via
Wroughton. It emerges near
Stratton St Margaret, becoming the A361 again at the junction with the
A419 which passes northeast of Swindon.
North Wiltshire and Gloucestershire This road links
Highworth to
Lechlade and has no pavement for the entire length apart from a small section in
Inglesham. It carries traffic at high speeds. across the
River Thames. The
Thames Path National Trail follows the verge for a little over one mile between Upper Inglesham and
Inglesham. On entering Lechlade, the road crosses the Grade II listed
Halfpenny Bridge, which marks the navigable limit of the
River Thames for powered craft. Lines painted onto the panels on the bridge parapets indicate the border between the counties of Wiltshire (to the south) and Gloucestershire (to the north).
Oxfordshire The road crosses into Oxfordshire a few miles north of Lechlade and heads towards
Cotswold Wildlife Park, Burford and
Chipping Norton passing many Oxfordshire villages on its way. It is also the boundary for the
Cotswolds AONB at Lechlade. It then enters
Banbury from the southwest as an arterial road passing the Banbury Cross, and heading north, the A361
multiplexes on the Southam Road roundabout of the
A422. For about two miles the route is signed as
A422, the dual carriageway Hennef Way until Junction 11 of the
M40.
Northamptonshire From there it heads northeast through the villages of
Wardington,
Chipping Warden,
Byfield,
Charwelton, and
Badby. A
relief road for Chipping Warden was constructed in 2021, in conjunction with neighbouring works for
HS2. Sections of land were purchased in the 1970s after the road was upgraded from the
B4038 to the A361 to straighten out some of the sharper corners but the vast majority of these works were never done. The road then multiplexes once more, this time with the
A45 just outside
Daventry. Once the A45 leaves Daventry for
Coventry, the remaining section of single carriageway ring road is signed as A361, before it once again turns north to
Kilsby to terminate on the
A5 at its northern end. ==Points of interest==