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Route of the A303

The famous and iconic road from London to the South West, and from work to holidays for many millions of people over the years, the A303 is bound up in British culture with ideas of summer, surfing, festivals and fun. For much of the year its alignment means it seems to carry traffic straight into the rising and the setting sun. It passes right by Stonehenge. There's at least one whole book about it and there are mentions in countless others. It even appears in song.

You can find your way home on the 303
You can let somebody know on the 303, on the 303

303 by Kula Shaker

Strictly speaking, the A30 is the road from London to the South West, running from Hounslow in West London to Land's End. In the early 1930s, it was already struggling to handle the holiday traffic every summer, so in 1934 a collection of back roads and B-roads running slightly to the north were reclassified as a new main road, the A303, to provide an alternative. The choice of route wasn't as arbitrary as it sounds — it was actually the route of a centuries-old road to the South West called the New Direct Road.

Over time, the A303 became the more important of the two roads, as it took a straighter line and passed through fewer towns. In the 1950s it became a trunk road, and in the early 1960s with the introduction of primary routes, it was the A303 that got green signs, relegating the A30 to a backwater where the two ran parallel. Today the A303 is the obvious choice from Hampshire to Devon and only local traffic uses the A30 to hop from town to town.

Unfortunately, the other thing the A303 is known for is chronic congestion. It's the fate of any road towards a summer holiday destination (M5 and A64, we are looking at you) to suffer congestion when everyone heads for the seaside at the same time. The A303 suffers this as much as any road, but the situation is made much worse by the inconsistent standard of the road. At various times in the twentieth century, contradictory decisions were taken. Sometimes, the A303 was to become a fast new expressway between the M3 and M5. At other times the motorway network was supposed to carry the traffic. Sometimes the upgrades to the road had to be high-standard dual carriageway. At other times a single-carriageway bypass would do. In the early 1970s the Government confidently expected the whole route would be dualled by the mid-1980s, but today the job remains half-done. As a result, for the whole of its route, the A303 switches between different types of road, widening and narrowing again, causing traffic jams wherever a lane ends and a set of traffic lights suddenly hold things up.

For a long time the A303 was completely stalled. Stonehenge — one of the road's most striking landmarks, and one of the world's most precious historic sites — made it politically too difficult to upgrade the road between Amesbury and Winterbourne Stoke, and if one part couldn't be turned into an expressway there was no point in doing the rest. Upgrade schemes elsewhere, long since put on hold, were fed slowly into a shredder and money was spent elsewhere.

But, as ever, contradictory decisions continue to be taken and the plan continues to change. As of 2015, the Stonehenge Tunnel plan has been resurrected, and if a dual carriageway will be dug under the sensitive landscape around Stonehenge then upgrades to the other "missing" sections suddenly become worthwhile again. There are now plans afoot to complete nearly all the parts that are still single-carriageway, with the dual carriageway branching off the A303 to follow the A358 to the M5 at Taunton. And just like before, it remains entirely possible that the plan will change, that the tunnel will be called off, that the A303 will be dualled to Honiton instead of the A358 to Taunton, or indeed that something else contradictory and unexpected will come along.

In the meantime — while we wait for news on what the latest plan might be, and whether money will be spent before someone else has another good idea — the A303 remains an entirely enjoyable and special road just as it is. It's not just famous and culturally important because of the places it links; it's also a memorable and interesting drive in its own right. It can feel more like a part of the holiday than part of the journey. So treasure the hills and the valleys, enjoy the sunrises and the sunsets, marvel at Stonehenge while it's still by the side of the road, grit your teeth through the traffic jams, and take pleasure in one of Britain's most remarkable A-roads, the A303.

You're not looking at the whole A303

This page only deals with the parts of the A303 that are classed as motorway or that have motorway characteristics. Any other sections of this road won't be featured here and will not count towards the mileage shown below.


Start Basingstoke (M3)
Finish Ilminster (A303)
Passes Popham, Salisbury, Yeovil
Length 78 miles
Connects to M3, A34

Road Schemes

CBRD's Road Schemes section has information on these schemes that are active or in planning on the A303.