A303 Sparkford to IlchesterRecently updated

Improving the single lane to a dual carriageway on the A303 between Sparkford and Ilchester, part of a programme of improvements to the A303/A30/A358.

Region:  South West
Start date:  TBC
Cost:  £100 to £250 million
Status:  PLANNED
Type:  Major Scheme
End date:  TBC
Programme:  A303 / A358 Corridor improvements

Progress report

Our statutory consultation on the A303 Sparkford to Ilchester dualling scheme has now closed. We’d like to thank everyone who participated in the consultation, using the opportunity to speak to the project team and share their feedback on the proposal. We'll now consider all the responses very carefully before moving on to the next stage of the scheme development.

From 23 April until the middle of June, a contractor working on our behalf will be carrying out some ground investigation surveys at a number of locations close to the A303 between Sparkford and Ilchester. The surveys are needed to better understand the geology and water table along the line of the developing proposal.

Equipment such as borehole drilling machines and small excavators will be used to take samples to help our understanding of the composition, properties and structure of the ground, and also to monitor the groundwater.

These surveys are vital as the information collected will inform engineering design decisions such as slope angles, construction depth, bridge foundations and drainage.

We have already spoken to anyone likely to be directly affected by these surveys, and do not otherwise expect there to be any other direct impact or road closures.

More information on this type of work, as well as other surveys that we undertake, can be found in the ‘documents section’ of this page below.

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What's next?

We will spend the next few months analysing the responses from the public consultation, and combining this information with the results of ongoing surveys.

A consultation report will be prepared, and this will be published ahead of our application for a Development Consent Order (DCO) later this year. A DCO is a special type of planning application, which is needed for a Nationally Significant Infrastructure Project (NSIP). Following the submission of the DCO application, the Planning Inspectorate will hold a public examination before making a recommendation to the Secretary of State for Transport who will decide whether or not the project should go ahead.


Date Event
2014 Scheme included in the Roads Investment Strategy
2015-2016 route identification
15 February to 29 March 2017 Non-statutory consultation on route options
October 2017 Announcement of preferred route
26 January – 9 March 2018 Statutory consultation on proposed scheme
Mid 2018 Submit planning application
2020 (TBC) Start on site

Why we need this scheme

The A303/A358 corridor is a vital connection between the south west, London and the south east. While much of the route is a dual carriageway, there are still over 35 miles of single carriageway. These sections act as congestion bottlenecks, particularly in the summer months and at weekends, causing delays to road users travelling between the M3 motorway and the south west and an increased risk of accidents.

This section of the A303 between Sparkford and Ilchester comprises a mix of dual and single lane carriageway, which leads to localised congestion, impacting adversely on journey times and reliability. This section also has a poor accident record as a result of poor junction alignment and visibility, and changes in road type.

We are proposing to dual this single carriageway section. The scheme will reduce congestion, improve journey times and make our network safer for customers.

View an overview map of the scheme.


The aims of the scheme include the following:

  • capacity: reduce delays and queues that occur during peak hours and at seasonal times of the year
  • safety: improve the safety of the network by providing additional capacity, reducing driver stress and enabling safer access to and from the motorway. It will also improve the non-motorised user routes in the area
  • environment: avoid unacceptable impacts on the surrounding natural and historic environment and landscape and optimise opportunities for enhancement
  • local communities: reduce community severance and promote opportunities for improving their quality of life
  • support economic growth: facilitate growth in jobs and housing by providing a free-flowing and reliable connection between the south east and the south west
  • connectivity: improve the connectivity of the south west to the rest of the UK and improve business and growth prospects
  • resilience: improve journey time reliability and resilience, and provide extra capacity to make it easier to manage traffic when incidents occur

The scheme in detail

Our proposal is for a dual carriageway that starts east of Podimore Roundabout and follows the alignment of the existing A303 to Downhead. Travelling eastwards, the route moves north of the existing A303 single carriageway, allowing the existing road to be retained for use as a parallel local road in this section. The route then rises up West Camel Hill before crossing over the existing A303 at the junction with Steart Hill/Howell Hill. The route then takes a southerly alignment briefly before meeting up with the existing road again to pass between Vale Farm and the MOD signal station at Eyewell/Traits Land.

Finally, the route then bypasses the existing Hazlegrove Roundabout to the north through the Registered Park and Garden associated with Hazlegrove House, before tying into the existing A303 Sparkford Bypass.

Project media files and documents

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Project timeline

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