A303 / A358 / A30 corridor improvements

Unlocking economic growth by upgrading the A303, A358 and the A30

In 2014, the Government – as part of its first Road Investment Strategy (RIS1) - announced that it wanted to unlock economic growth in the South West by upgrading the A303, A358 and A30 in Cornwall. It wanted to create high quality dual carriageways, transforming journeys, and better connecting the region with London and the South East.  

The A303 is a main arterial route, running across the country. Linking up with the M3 in Hampshire, it passes the world-famous Stonehenge monument through the surrounding World Heritage Site and carries an average 26,000 vehicles a day, with that figure increasing significantly during the summer months.

Journey times along the A303 are notoriously unreliable, and this causes a real problem for everyone: local people struggle to just go about their normal business, logistics companies trying to make ‘just in time’ deliveries simply can’t get through, and for the thousands of tourists flocking to holiday destinations in Wiltshire, Somerset, Devon and Cornwall it can mean a dismal start and end to their summer breaks. 

The A358 between Southfields Roundabout on the A303 and M5 at Taunton is also being developed, to form part of the strategic route to and from the South West. The vision is that traffic will use a combination of the A303 and the A358 to make journeys to and from Devon and Cornwall, reducing the strain on the A30 between Ilminster and Honiton. That section can’t be upgraded in the same way as the A358 can, as it runs through the Blackdown Hills, a designated ‘Area of Outstanding Natural Beauty’.

And finally, the A30 between Chiverton and Carland Cross is being upgraded to dual carriageway too. This upgrade is incredibly important for Cornwall’s future. It's the only remaining stretch of single carriageway on the A30 between Camborne and the M5 at Exeter.  By improving it we intend to resolve problems with congestion, which have held the Cornish economy back for too long.

So, what are we doing?

The aim is to upgrade all the remaining sections of single carriageway along the A303/A358 to dual carriageway, and also dual the A30 in Cornwall.   To achieve this, a programme of eight improvement schemes along the A303/A358 have been identified.  The desire is to eventually create safe and reliable roads where a ‘mile-a-minute’ travel is the norm.

During the first roads period (2015 – 2020) the Government asked us to develop the:

  • A303 Stonehenge scheme
  • A303 Sparkford to Ilchester dualling scheme
  • A358 Taunton to Southfields dualling scheme
  • A30 Chiverton to Carland Cross dualling scheme

A303 A358 A30 corridor improvements

Eight improvement schemes along the A303/A358 were originally identified.

We’re now in the second roads period (RIS2), which runs from 2020 to 2025, and our aim is to continue working on these schemes, getting them all through the planning process and into construction. At the same time, we’re also looking at the second phase of A303 upgrades, which we expect to deliver in RIS 3, from 2025 onwards (subject to funding, and inclusion in future road investment strategies).

Find out more about each scheme below: