A358 Taunton to Southfields

We’re proposing to upgrade the A358 to dual carriageway between Southfields Roundabout on the A303 and the M5 at Taunton. The delivery of this scheme is part of a long term aim to create a high-quality dual carriage way link between London and the South East and the South West.

Start date TBC
End date TBC
Cost £250 to £500 million

Latest updates

  • 13 May 2022

    Supplementary consultation on design changes

    National Highways is consulting on design changes for the proposed upgrade to the A358 between Taunton and Southfields roundabout.

    The consultation will run from Tuesday 24 May until 11.59pm on Sunday 26 June 2022.

    We’re looking to upgrade approximately 8.5 miles (13.6 km) of the A358 to a high-quality and high-performing dual carriageway. Since our 2021 consultation we’ve made some changes to our preliminary design which will improve safety and access to local roads and reduce the impact on communities, the environment and the local landscape.

    The supplementary consultation starts on Tuesday 24 May and runs until Sunday 26 June and there are lots of way to have your say. Your feedback will help us develop our application for a Development Consent Order (DCO), the type of planning permission needed for the scheme. 

    When the supplementary consultation opens on 24 May you will be able to find out more about the proposals and have your say, by visiting National Highways’ online exhibition or one of our consultation events. Our project team will be on hand at our face to face events and webinars to answer your questions. 

    If you do not have access to the internet or experience problems downloading the consultation materials, National Highways can send, free of charge, one printed copy of documents including the consultation booklet, feedback questionnaire, and non-technical summary of the Preliminary Environmental Information Report, to your home. 

    You can request printed copies or a call back by emailing A358TauntontoSouthfields@nationalhighways.co.uk or calling our customer service line on 0300 123 5000. 

    How to find out more

    There are lots of ways to find out more about the design changes to the A358 Taunton to Southfield’s Dualling Scheme.  

    From 24 May you can visit the virtual consultation room by following the links on this webpage. In this virtual room you’ll find all the information you’d normally see in a physical exhibition – but with the added benefit of being able to visit at any time of the day or night. 

    You can also take part in a webinar where members of our project team will be able to answer your questions. These start on 25 May. All the details on dates and how to sign up will be on this webpage.

    If you prefer to meet our team face to face and have your say there are in-person events in Ilminster and Taunton. On 26 May the team is at Monks Yard, Horton Cross Farm, Horton Cross, Ilminster, TA19 9PT from 11am to 8pm. On 8 June members of the project team are  at Somerset County Cricket Ground, St James Street, Taunton, TA1 1JT. On 11 June they will be at Taunton Racecourse, Orchard Portman, Taunton, TA1 2UA from 11am to 6pm.

    Having your say in the A358 Taunton to Southfields supplementary consultation is easy 

    From 24 May you can submit a response by using one of the methods below, which are all free to use. Please note, we cannot guarantee that responses sent by any other means will be considered.  

    Online response form 

    Fill in the online questionnaire


    Post your response for or comments to: 


    The Freepost address is the only text needed on the envelope, and no stamp is required


    Email your comments to: A358TauntontoSouthfields@nationalhighways.co.uk 

    It's important to make sure that your comments are sent before the consultation closes at 11.59pm on 26 June 2022. 





  • 14 February 2022

    Consultation summary report available

    Following our Statutory Consultation, which ran from 12 October to 22 November 2021, our public consultation summary report is available.  In this report we explain the consultation methodology and outline the key themes from the public consultation. It also gives details of what will happen next. 

    This report is an interim document. We will be submitting the full findings of the consultation in our consultation report which forms part of our Development Consent Order application planned for later this year.

  • 15 December 2021

    Post consultation survey

    Now the consultation period for the scheme has come to an end, we would like to gather feedback on the consultation process, including the events that took place both in-person and virtually.

    We would be grateful if you could give us a few minutes of your time to complete a short survey, which should take no longer than five minutes to complete. Any comments or suggestions you have would be greatly appreciated and will help us to improve the way we run our consultations in the future.  

    This survey will remain open until Tuesday 4 January 2022 .

  • 30 November 2021

    Consultation closes 

    Consultation on the A358 Taunton to Southfields Dualling Scheme reached its conclusion on Monday 22 November. 

    During this consultation period we held three in-person events, which saw more than 600 people join us to talk to project experts and see the consultation material in person. We also held nine webinars, hosted a virtual exhibition room and ran a series of webchats with the project team. 

    What happens next  

    All feedback we have received during the consultation period will be formally reviewed by the project team and compiled into a consultation report. This report will form part of our planning application for a Development Consent Order (DCO), which we expect to submit in 2022.

  • 12 October 2021

    Our consultation is now live

    We're consulting on our proposals to upgrade the A358 Taunton to Southfields to dual carriagewayThis will improve road safety, reduce traffic congestion and improve connectivity for road users and local communities, while unlocking economic growth in Somerset and the South west. 

    Now it’s your chance to have your say on our updated proposals.   

    The consultation runs from 12 October to 22 November 2021 - visit our consultation website to find out more about how you can get involved. 

  • 28 September 2021

    Have your say: we're consulting 12 October - 22 November


    We will be consulting on our proposals to upgrade the A358 between Taunton and Southfields roundabout from 12 October to 22 November 2021. The feedback from this consultation will help us develop our application for a Development Consent Order (planning consent) that we plan to submit next year. 

    You will be able to view our consultation plans on this webpage from 12 October 2021. 

    How to find out more 

    Online exhibition  

    From the 12 October, one of the best ways to find out about our proposals will be to visit our virtual exhibition room via this webpage. Here, you will be able to learn more about the project, study detailed plans and put your questions to our team.  

    Members of our team will be available to answer your questions via a webchat function at the following times: 



    Tuesday 12 October 

     4pm – 7pm 

    Wednesday 13 October 

    11am – 2pm 

    Friday 15 October 

    8am – 11am  

    Friday 15 October 

    3pm – 6pm  

    Monday 18 October 

    12pm – 3pm  

    Wednesday 20 October  

    10am – 1pm 

    Wednesday 20 October 

    6pm – 9pm  

    Friday 22 October 

    9am – 12pm  

    Friday 22 October 

    3pm – 6pm  

    Thursday 18 November 

    3pm – 6pm  

    Friday 19 November 

    9am – 12pm 


    Outside of these times, you will be able to submit questions to our team who will get back to you via email. 


    We’re hosting some themed webinars on Microsoft Teams with our project team, focusing on different topics and specialist areas. At these events, our team will give a short presentation and then take questions from attendees. You can submit your questions using the chat function, which can be used anonymously.  

    You can register for the below sessions by emailing: A358TauntontoSouthfields@highwaysengland.co.uk 




    Consulting on the A358 Taunton to Southfields dualling scheme 

    Thursday 14 October 


    Section 1 – M5 junction 25 to Mattock’s Tree Green junction 

    Wednesday 20 October 


    Section 2 – Mattock’s Tree Green junction to Griffin Lane 

    Thursday 21 October 


    Section 3 – Griffin Lane to Ashill junction  

    Thursday 21 October 


    Section 4 – Ashill junction to Southfields roundabout   

    Friday 22 October 


    Walking, cycling and horse riding, including disabled users 

    Monday 1 November 


    The environment 

    Tuesday 2 November 


    Traffic modelling 

    Thursday 4 November 


    Consulting on the A358 Taunton to Southfields Dualling Scheme 

    Thursday 18 November 



    Public consultation events 

    Visit one of our face-to-face events to find out more about the proposals and chat to our team. 





    Taunton Racecourse, Orchard Portman, Taunton, TA3 7BL  


    Tuesday 19 October 

    2pm - 8pm 

    Monks Yard (Conference Room), Horton Cross Farm, Horton Cross, Ilminster, Somerset, TA19 9PT  


    Saturday 23 October 

    11am - 6pm 

    Holiday Inn Taunton, Deane Gate Avenue, Taunton, Somerset, TA1 2UA  


    Wednesday 3 November 

    11am - 6pm 

    Telephone surgery 

    You can book a call back from a member of the project team who will answer your questions on the proposed changes. Call backs will be made Monday to Friday, 12pm to 7pm, between 12 October and 22 November. 

    You can request a call back by emailing: A358TauntontoSouthfields@highwaysengland.co.uk or calling 0300 123 5000. 

    Home delivery 

    If you do not have access to the internet or experience problems downloading the consultation materials, we can send you free of charge one printed copy of the consultation booklet, feedback questionnaire and non-technical summary of the Preliminary Environmental Information Report. 

    You can request printed copies by emailing A358TauntontoSouthfields@highwaysengland.co.uk or calling 0300 123 5000.

    Deposit points

    You can also visit one of the information points below to pick up a paper copy of the consultation booklet, feedback questionnaire and non-technical summary of the Preliminary Environmental Information Report. 

    ·Taunton Library, Paul Street, Taunton, TA1 3XZ

    ·South Petherton Library, 3 St James's Street, South Petherton, TA13 5BS

    ·Martock Library, North Street, Martock, TA12 6DL

    ·Priorswood Library, Hillside Children's Centre, Eastwick Rd, Taunton, TA2 7HD

    · Ilminster Library, Ditton Street, Ilminster, TA19 0BW (hard copy of the Preliminary Environmental Information Report will also be available for inspection at this location)

    ·Chard Library, Holyrood Street, Chard, TA20 2YA

    ·Somerset County Council mobile library

    ·Ilminster Meeting House & Arts Centre, 35 East Street, Ilminster, TA19 0AN

    ·Henlade Post Office, Henlade, Taunton, TA3 5DH

    ·Blackbrook Leisure Centre & Spa, Blackbrook Way, Taunton, TA1 2RW

    · Somerset West and Taunton Council, Deane House, Belvedere Road, Taunton, Somerset, TA1 1HE (hard copy of the Preliminary Environmental Information Report will also be available for inspection at this location)

    How to have your say 

    From 12 October you can submit a response by using one of the methods below, which are all free to use. Please note, we cannot guarantee that responses sent by any other means will be considered.  

    Online response form 

    Fill in the online questionnaire. 


    Post your response for or comments to: 


     The Freepost address is the only text needed on the envelope, and no stamp is required. 


    Email your comments to: A358TauntontoSouthfields@highwaysengland.co.uk 

  • 20 September 2021

    Ground investigation surveys

    traffic surveys

    As we develop our plans for the A358 upgrade scheme, some of our teams will be out and about around the route to complete essential surveys of the local area and environment. This includes ground investigation surveys which we use to show all sorts of information – such as buildings, roads, population numbers, height and flooding data. This information helps us to develop our plans for the scheme as carefully and accurately as possible.

    Our teams will also be working on important archaeological surveys. These help to locate historical sites or materials and allow us to make informed decisions about our proposals and the areas where we will look to carry out works in the future.

    You can read more about the different types of surveys we'll be doing in the 'Environmental' section further down this webpage.

    Site compound

    As we complete these surveys, some of our teams will be working from a small site in the area. This site compound will be located away from any residential areas and we will make sure that any disruption is kept to a minimum.

    Road closures 

    To carry out the surveys safely there will be some temporary lane and local road closures. These closures will take place on weeknights only, between 8pm and 6am. We’ve provided a summary of the dates and closures below. 

    From Monday 9 – 16 August 2021 and from Monday 13 – 27 September 2021 

    We will be reducing traffic down to a single lane from Southfields roundabout heading towards Taunton. As this is a single lane closure, we will not be introducing a diversion route, we will use a  a temporary traffic lights system. Emergency access will be maintained by our traffic management contractor Alliance Highway. 

    From Wednesday 29 September – 1 October 2021  

    We will need to close some local roads which connect to the A358. We will carry out these closures one at a time and put a diversion route in place. These closures will take place on weeknights only, between 9pm and 6am Emergency access will be maintained by our traffic management contractor Alliance Highway. To find more information visit www.streetworks.org.uk/live-traffic-works-map/ where you can see an interactive map of the locations and diversions.

    If you have any questions or want to speak to a member of our team, please email us at A358TauntontoSouthfields@highwaysengland.co.uk or call us on 0300 123 5000.

  • 20 May 2021


    We’ve now awarded a £328 million contract to Taylor Woodrow Plus to design and build the A358 Taunton to Southfields upgrade scheme. We can now update you with what this means for the scheme, what you might see happening along the route and how and when you can have your say on the plans.

    Upcoming closures

    To help us to design the route as best we can, we need to carry out surveys into the current state of the road.

    To carry out these surveys safely we will be introducing a single lane of traffic between Southfields Roundabout and Hatch Green, and an additional one between Hatch Green and Ash Cross from Monday 7 June to Friday 2 July. These closures will take place on weeknights only, between 8pm and 6am. Because this is a single lane closure, we will not be introducing diversion lanes, only a temporary traffic lights system. Emergency access will also be maintained at all times. 

    Environmental surveys

    The countryside along the route is home to some incredible plants and animals - many of which are protected by law - and we need to take steps to avoid them or reduce our impact. That’s why you may see our team out and about carrying out various surveys to look into things like:

    • Air quality
    • Cultural heritage
    • Changes to how the local scenery will look
    • Biodiversity
    • Birds
    • Reptiles
    • Great crested newts
    • Water quality sampling

    With these surveys and design plans well underway, we are continuing to plan for our public consultation, which we expect to take place later this year. Before that, we will be meeting regularly with local community organisations and representatives.

    This will allow us to give updates on the route and to also get important feedback which will help us to shape our final designs. We will be also be speaking to special interest groups, such as walkers, cyclists and horse riders, to make sure that our plans can cater for different road users as much as we can.



  • 27 November 2020

    Early works on the scheme’s preliminary design progressing

    We are pleased to be able to confirm that the A358 scheme has now been allocated to Taylor Woodrow following a competitive tender process through the Regional Delivery Partnerships framework.

    We are now in the process of finalising the scheme contract with Taylor Woodrow, which is scheduled to be awarded early next year. Taylor Woodrow are also progressing early works on the scheme’s preliminary design.

    The scheme is classed as a Nationally Significant Infrastructure Project (NSIP) under the Planning Act 2008. This means we’ll need to make an application for a special type of planning permission called a Development Consent Order (DCO) to gain authorisation to acquire the land and construct the scheme.

    Before we can submit our application for a DCO we will hold a statutory public consultation on the design where we invite comments on our proposals. We are still finalising the future programme for the scheme, but we anticipate holding this consultation in 2021.

    You can find out more about NSIPs on the Planning Inspectorate's website. Alternatively you can watch our short animation which explains the process in simple terms.

  • 24 October 2019

    Preferred route announcement

    Since we announced our preferred route in June, we’ve been carrying out surveys to help inform the scheme design ahead of consultation. In September we held our second Community Liaison Forum and asked the members of the forum to give feedback on the route to help us develop the scheme design. We’ve grouped the feedback given under four headings:

    • local links and community severance
    • process, timeline and scope of works
    • rationale and impact of the route regarding housing development and economic growth with a focus on job creation
    • focus on the location and performance of proposed and existing junctions and access points

    You can see more detail about the feedback in the meeting note in the 'Consultations' folder under the project information section.

    We’ve also been busy creating an animation to explain the process we go through when designing a road scheme such as the A358. We hope this will help you understand the level of detail you can expect to see at each stage.

Project information


The A303/A358 corridor is a vital connection between the South West and London and the South East. While much of the corridor 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, and they add to an increased risk of accidents.  

Currently most of the A358 is a single lane and has many local roads and private accesses joining directly with it. It’s often congested and is a source of frustration for local people, and those using the road to travel longer distances.  

Many road users try to avoid the traffic congestion by diverting onto smaller local roads, which then increases the level of traffic in surrounding villages. 

To address this, we’re proposing to upgrade an 8.5 mile section of the A358 between Southfields Roundabout on the A303 and the M5 at Tauntonto a high quality dual carriageway.  

In 2019 we made our preferred route announcement for the improvement scheme, confirming that we’ll be taking a modified version of the pink option forward. You can find out more about the options consultations and the chosen route.

In delivering the scheme, we’re aiming to:

  • improve the capacity of the road to reduce delays and queues that occur during peak hours and at key times of the year i.e. the height of summer.
  • support economic growth, facilitating growth in jobs and housing by providing a free-flowing and reliable connection between the South East and the South West
  • make the road safer, by providing additional capacity and reducing driver stress. We’ll also improve routes for pedestrians, cyclists, horse riders in the area.
  • protect the environment and look for opportunities to improve it, minimising any unnecessary impact of the scheme on the surrounding natural and historic environment and landscape
  • work with local communities to reduce the impact of the road in terms of community severance, and look for ways to improve local peoples’ quality of life
  • make journey times more reliable and resilient; by providing more capacity it will become easier to manage traffic when incidents occur


Traffic information

Information about scheduled roadworks and events on our motorways and major roads.

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