It links points on the edges of that county's two principal cities, Exeter and Plymouth, by an indirect and largely coastal route.

The indented nature of the South Devon coast means that the road is usually out of sight of the sea, but the many rivers and estuaries are crossed by bridges and, in one case, a cable ferry.

Both these branches were historically part of the A38, and the first crosses the Countess Wear bridges over the River Exe and the Exeter Canal, once infamous for the delays caused on what was then the principal route to the holiday resorts of Devon and Cornwall.

The only remaining roadsign indicating this is a wrong direction facing B3199 sign on a lamppost in Teignmouth Hill, Dawlish.

The road then runs into the suburbs of Plymouth, bypassing Plymstock before crossing the estuary of the River Plym on the Laira Bridge.

The A379 ends on the west side of the Plym, joining the A374 just over 1 mile (1.6 km) east of Plymouth city centre.