M4 junctions 3-12: smart motorway

Making the M4 a ‘smart motorway’ between junctions 3 and 12.

Region:  South East
Start date:  2018
Cost:  £848 million
Status:  CURRENT
Type:  Major Scheme
End date:  2022
Programme:  Smart Motorways

Progress report

Central reservation works between junctions 8/9 at Maidenhead and 10 at Wokingham are ahead of schedule while our new office and logistics compound near junction 10 is almost complete and due to open in the new year. Preparation work on bridges and structures between junctions 7 at Slough West and 8/9 also begins in December, before full works start in 2019.

Christmas construction closedown

The M4 smart motorway project will shut down from 21 December 2018 to 7 January 2019. This means that there will not be any planned closures of the motorway or any construction works, night time or otherwise, over the festive season.

The narrow lanes will remain in place for safety reasons but the only activities during this period will be maintenance and monitoring of traffic and work sites. You will be able to get in touch with the team as normal during this time.

What's next?

We are also planning our public engagement events for next year. In March and April 2019 we will be holding the next set of Public Information Events for areas between junctions 3 at Hayes and junction 7 ahead of the next phase of the works. These events will be published on this page when they have been scheduled.

There are several overnight full closures currently planned in December. The best way to keep up to date with the various closures, including slip road closures, is the Traffic England website.

Note: In the event of poor weather conditions or other issues out of our control, planned works may be postponed at short notice. If works complete ahead of schedule the motorway may reopen early. Signage will be in place to update road users of changes.

Timeline

Date Event
March 2008 Advanced motorway signalling and traffic management feasibility study identified this motorway link as a priority for additional capacity
2009 Department for Transport announces a programme of smart motorways, including this scheme
2010 Scheme development commenced
2013 Roads Minister announces funding for this scheme
November 2014 to December 2015 Pre-application consultation
January to February 2015 Speed limit consultation
30 March 2015 Development Consent Order submitted
27 April 2015 Planning application accepted for examination
July 2015 CH2M and Arcadis appointed to develop detailed scheme design
July 2015 Balfour Beatty Vinci Joint Venture appointed to develop construction methodology and programme
2 September 2016 Secretary of State decision
15 October 2016 High Court Challenge period ended
March 2017 Start of preparation works
July 2018 Public information exhibitions
Autumn 2018 Start of main works
Spring 2022 Smart Motorway complete and operating

News

Carrying out construction works at night

We carry out various works at night in order to minimise disruption to road users during peak traffic hours. We also have to do certain works at night if it is not possible to complete these during daylight hours. Some of these essential works can be noisy for which we apologise for any inconvenience. Please do get in touch if you have any concerns about works at night.

Vegetation clearance work underway

One of the most important activities taking place at present is clearing and maintaining vegetation. This is required to create space and facilitate construction of the permanent works and install the technology for the new smart motorway. Due to limited space between the motorway fence and hard shoulder this often (but not always) requires complete clearance within the highway boundary. We are also clearing vegetation along the fence line to allow CCTV and temporary power cables to be connected. There are however areas of retained vegetation which are being left where there is sufficient room to allow this and these areas will be retained throughout construction. All works are carried out under strict guidelines and monitored to minimise impact on local wildlife and the amenity of local residents. Please do contact us with any concerns about vegetation clearance near your home.

We carry out various works at night in order to minimise disruption to road users during peak traffic hours. We also have to do certain works at night if it is not possible to complete these during daylight hours. Some of these essential works can be noisy for which we apologise for any inconvenience. Please do get in touch if you have any concerns about works at night.

One of the most important activities taking place at present is clearing and maintaining vegetation. This is required to create space and facilitate construction of the permanent works and install the technology for the new smart motorway. Due to limited space between the motorway fence and hard shoulder this often (but not always) requires complete clearance within the highway boundary. We are also clearing vegetation along the fence line to allow CCTV and temporary power cables to be connected. There are however areas of retained vegetation which are being left where there is sufficient room to allow this and these areas will be retained throughout construction. All works are carried out under strict guidelines and monitored to minimise impact on local wildlife and the amenity of local residents. Please do contact us with any concerns about vegetation clearance near your home.

Indicative timings of the works

This is the longest smart motorway project in England to date (51km, 32 miles). To minimise disruption to our customers we will need to work on different stages at different times.

Our current intention for the phasing of construction, is to start at junction 8/9 and progress west towards junction 10. In tandem we will start work on four bridges between junction 8/9 and junction 7. The more complex section of the scheme, progressing east from junction 8/9 towards junction 3, will be started in May 2019.

The table below indicates which sections of motorway we expect to be working on at any given time.

Timetable subject to governance, funding approval and discharge of the DCO.

Link Start End
Junction 12 to 11 May 2020 February 2022
Junction 11 to 10 May 2020 January 2022
Junction 10 to 8/9 September 2018 May 2020
Junction 8/9 to 6 May 2019* December 2021
Junction 6 to 5 December 2019 March 2022
Junction 5 to 4b October 2019 March 2022
Junction 4b to 3 January 2020 March 2022

* Mobilisation work to 4 structures in junction 8/9 to 7 link will also start in late autumn 2018

Bridge works

Much of the M4 was originally built as a two-lane dual carriageway, and has been upgraded over the years. Eleven bridges over the motorway need to be replaced to make room for a new lane where there is no existing hard shoulder.

To limit local disruption, new bridges will be built next to the existing ones, before the old one is demolished. However, where there is not enough space for this, some bridges will be demolished first, then a new bridge built in the same place.

Where the motorway passes over, for example, the River Thames at Bray and the railway line to Windsor, we will need to widen structures to support the new smart motorway.

Considerate construction

Wherever possible, noisier works will be undertaken during daytime hours to reduce disturbance.

There will be temporary closures of the carriageway and slip roads at night on some occasions. In these instances, the closure will be advertised, and advance warning signs and clearly signed diversions will be put in place. You can use the Roadworks section below to find information about roadworks as the scheme progresses.

The construction of the scheme will be governed by the Construction, Design and Management Regulations, and we will be a member of the Considerate Constructors scheme which will help ensure that we are a good and responsible neighbour.

Further details will be provided on these project web pages as they become available both before and during construction. Please sign up for updates using the link on the right if you would like to receive notifications when the web page is updated.

Why we need this scheme

The M4 is the main strategic route between London, the West of England and Wales. It connects people, communities and businesses, carrying on average 130,000 vehicles per day and is prone to congestion.

Highways England will be improving the M4 between junction 3 at Hayes and junction 12 at Theale by upgrading it to a smart motorway which will provide much needed capacity and support the economy and facilitate economic growth within the region. This means there will be:

  • an additional lane for traffic increasing capacity to reduce congestion
  • more technology on the road to smooth flows and manage incidents
  • more reliable journeys

The scheme in detail

This scheme will use the latest technology to improve journeys by monitoring traffic flow and setting speed limits accordingly. This helps to keep traffic moving smoothly, instead of continually stopping and starting.

Information about road conditions and speed limits will be displayed to drivers on electronic road signs.

The proposal also involves converting the hard shoulder permanently to a traffic lane. This will create much needed extra capacity necessary to support economic growth.

Key changes to the motorway

All Lane Running: between junctions 3 and 12 the hard shoulder will be converted to a traffic lane, so that there are four lanes available for use by road users. Between junctions 4 and 4b, there will be five lanes. Where a hard shoulder does not currently exist, the motorway will be adapted to create a minimum of four lanes. The barrier in the central reservation will be replaced by a new concrete barrier.

Through junction running: This enables a consistent number of lanes to pass through the junction, reducing the need to change lane for vehicles staying on the motorway. Through-junction running will be in place at junctions 4, 5, 6, 7, 8/9 and 11 and at the Reading motorway service area.

Bridge works: To accommodate the new smart motorway:

  • 11 bridges carrying local traffic over the motorway will need demolition and replacement
  • 4 bridges that carry the motorway over roads, railways and rivers will need widening
  • 2 subways under the motorway will also need lengthening

Emergency areas (EAs): there will be new high visibility Emergency Areas between junctions 3 and 12. Places of relative safety will be every 1.12 miles on average and no more than 1.6 miles apart. If you are driving at 60mph you will pass one approximately once a minute.

Aims

The objectives of the proposed scheme are to:
  • reduce congestion
  • smooth the flow of traffic to improve journey times
  • make journeys more reliable
  • support the economy and facilitate economic growth within the region, by providing much needed capacity on the motorway
  • continue to deliver a high level of safety performance on the network using smart motorway techniques and minimise environmental impacts of the scheme

Development Consent Order

The DCO process was established by the Planning Act 2008 and is used for certain large and complex schemes (including highway improvements) that have been designated as a Nationally Significant Infrastructure Project (NSIP) by the Government.

The benefits of the DCO process include extensive pre-application consultation, detailed analysis, including a full Environmental Impact Assessment, and examination by an independent inspector before the final decision is made.

Development Consent Order – requirements register

We made a commitment to publish and update a register listing the requirements to be completed as part of the Development Consent Order (specified under the Register of Requirements in Schedule 2). This sets out:

  • each requirement
  • whether the requirement needs approval by the Secretary of State (or other duty holder)
  • whether any approval has been applied for or given

Environmental impact

As part of the DCO planning process, a full Environmental Impact Assessment was carried out and has been used to inform the design of the project. This included assessments and design of mitigation where needed for:

  • air quality
  • cultural heritage
  • landscape
  • ecology and nature conservation
  • geology and soils
  • materials
  • noise and vibration
  • effects on all travellers
  • community and private assets
  • road drainage and the water environment

During the examination of the application, further environmental protections were requested and planning requirements attached to the consent.

Project media files and documents

Project timeline

Planned roadworks

Roadworks and Events for England

The latest incident information for England's motorway and trunk routes provided by Highways England

Location : The M3 eastbound between junctions J3 and J2 . Lane Closures : Lane one is closed. Reason : Road repairs. Status : Currently Active. Period : expect disruption until 06:00 on 16 December 2018. Lanes Closed : There is one of four lanes closed.
Posted: December 15, 2018, 10:00 pm
Location : The M4 westbound between junctions J8 and J10 . Lane Closures : Lanes 2 and 3 are closed. Reason : Roadworks. Status : Currently Active. Period : expect disruption until 07:00 on 16 December 2018. Lanes Closed : There are two of three lanes closed.
Posted: December 15, 2018, 9:47 pm
Location : The M4 eastbound between junctions J10 and J8 . Lane Closures : Lanes 2 and 3 will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : From 21:00 on 16 December 2018 to 05:30 on 17 December 2018. Schedule : Expect disruption everyday between 20:00 and 06:00 from 17 December 2018 to 20 December 2018. Schedule : From 20:00 on 20 December 2018 to 05:30 on 21 December 2018. Schedule : Expect disruption everyday between 20:00 and 05:30 from 7 January 2019 to 11 January 2019. Lanes Closed : There will be two of three lanes closed.
Posted: December 15, 2018, 8:40 pm
Location : The M4 westbound between junctions J10 and J11 . Lane Closures : The hard shoulder, lanes 1 and 2 are closed. Reason : Roadworks. Status : Currently Active. Period : expect disruption until 07:00 on 16 December 2018. Lanes Closed : There are two of three lanes closed.
Posted: December 15, 2018, 8:35 pm
Location : The M4 westbound between junctions J6 and J10 . Lane Closures : Lanes 2 and 3 will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : From 21:00 on 16 December 2018 to 05:30 on 17 December 2018. Schedule : Expect disruption everyday between 20:00 and 05:30 from 17 December 2018 to 21 December 2018. Schedule : Expect disruption everyday between 20:00 and 05:30 from 7 January 2019 to 11 January 2019. Schedule : Expect disruption everyday between 20:00 and 07:00 from 11 January 2019 to 13 January 2019. Lanes Closed : There will be two of three lanes closed.
Posted: December 15, 2018, 10:33 am
Location : The M4 westbound between junctions J6 and J10 . Reason : Roadworks scheme is planned. Status : Pending. Schedule : From 21:00 on 16 December 2018 to 07:00 on 9 February 2019.
Posted: December 15, 2018, 10:33 am
Location : The M4 eastbound between junctions J10 and J7 . Reason : Roadworks scheme is planned. Status : Pending. Schedule : From 21:00 on 16 December 2018 to 07:00 on 9 February 2019.
Posted: December 15, 2018, 10:32 am
Location : The M4 eastbound between junctions J10 and J7 . Lane Closures : Lanes 2 and 3 will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : From 21:00 on 16 December 2018 to 05:30 on 17 December 2018. Schedule : Expect disruption everyday between 20:00 and 05:30 from 17 December 2018 to 21 December 2018. Lanes Closed : There will be two of three lanes closed.
Posted: December 15, 2018, 10:32 am
Location : The M4 eastbound between junctions J11 and J10 . Lane Closures : Lanes 1 and 2 will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : Expect disruption everyday between 20:00 and 05:30 from 17 December 2018 to 21 December 2018. Lanes Closed : There will be two of three lanes closed.
Posted: December 15, 2018, 7:01 am
Location : The M4 eastbound between junctions J11 and J8 . Lane Closures : Lanes 1 and 2 will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : Expect disruption everyday between 20:00 and 05:30 from 17 December 2018 to 21 December 2018. Lanes Closed : There will be two of three lanes closed.
Posted: December 15, 2018, 7:01 am
Location : The M4 eastbound between junctions J6 and J5 . Lane Closures : Lanes 1 and 2 will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : Expect disruption everyday between 20:00 and 05:30 from 17 December 2018 to 21 December 2018. Schedule : Expect disruption everyday between 20:00 and 05:30 from 24 December 2018 to 28 December 2018. Schedule : Expect disruption everyday between 20:00 and 05:30 from 31 December 2018 to 4 January 2019. Schedule : Expect disruption everyday between 20:00 and 05:30 from 7 January 2019 to 11 January 2019. Lanes Closed : There will be two of three lanes closed.
Posted: December 14, 2018, 11:21 am
Location : The A404M southbound between junctions J9A and J9 . Lane Closures : Lane one will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : From 21:00 on 16 December 2018 to 05:30 on 17 December 2018. Schedule : Expect disruption everyday between 20:00 and 05:30 from 17 December 2018 to 19 December 2018. Lanes Closed : There will be one of two lanes closed.
Posted: December 14, 2018, 11:21 am
Location : The A329M westbound. Reason : Roadworks are planned. Status : Pending. Schedule : From 21:00 on 16 December 2018 to 05:30 on 17 December 2018. Schedule : Expect disruption everyday between 20:00 and 05:30 from 17 December 2018 to 19 December 2018. Lanes Closed : All lanes will be closed.
Posted: December 14, 2018, 11:21 am
Location : The A329M eastbound. Reason : Roadworks are planned. Status : Pending. Schedule : From 21:00 on 16 December 2018 to 05:30 on 17 December 2018. Schedule : Expect disruption everyday between 20:00 and 05:30 from 17 December 2018 to 19 December 2018. Lanes Closed : All lanes will be closed.
Posted: December 14, 2018, 11:21 am
Location : The M4 westbound between junctions J7 and J10 . Reason : Roadworks scheme is planned. Status : Pending. Schedule : From 21:00 on 16 December 2018 to 05:30 on 19 December 2018.
Posted: December 14, 2018, 11:21 am
Location : The M4 westbound between junctions J7 and J10 . Lane Closures : Lanes 1, 2 and 3 will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : From 21:00 on 16 December 2018 to 05:30 on 17 December 2018. Schedule : Expect disruption everyday between 20:00 and 05:30 from 17 December 2018 to 19 December 2018. Lanes Closed : All lanes will be closed.
Posted: December 14, 2018, 11:21 am
Location : The M4 westbound exit slip at junction J10 . Lane Closures : Lanes 1 and 2 will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : From 21:00 on 16 December 2018 to 05:30 on 17 December 2018. Schedule : Expect disruption everyday between 20:00 and 05:30 from 17 December 2018 to 19 December 2018. Lanes Closed : All lanes will be closed.
Posted: December 14, 2018, 11:21 am
Location : The M4 westbound entry slip at junction J8 . Reason : Roadworks are planned. Status : Pending. Schedule : From 21:00 on 16 December 2018 to 05:30 on 17 December 2018. Schedule : Expect disruption everyday between 20:00 and 05:30 from 17 December 2018 to 19 December 2018. Lanes Closed : All lanes will be closed.
Posted: December 14, 2018, 11:21 am
Location : The A308M westbound between the junctions with the A308 and the M4 . Lane Closures : Lane one will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : From 21:00 on 16 December 2018 to 05:30 on 17 December 2018. Schedule : Expect disruption everyday between 20:00 and 05:30 from 17 December 2018 to 19 December 2018. Lanes Closed : There will be one of two lanes closed.
Posted: December 14, 2018, 11:20 am
Location : The A404M southbound entry slip at junction J9B . Lane Closures : Lane one will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : From 20:00 on 18 December 2018 to 06:00 on 19 December 2018. Lanes Closed : There will be one of two lanes closed.
Posted: December 14, 2018, 6:01 am
Location : The A404M southbound between junctions J9B and J9A . Lane Closures : Lane one will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : From 20:00 on 18 December 2018 to 06:00 on 19 December 2018. Lanes Closed : There will be one of two lanes closed.
Posted: December 14, 2018, 6:01 am
Location : The A404 southbound between the A4130 and the junction with the A4 . Lane Closures : Lane one will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : From 20:00 on 18 December 2018 to 06:00 on 19 December 2018. Lanes Closed : There will be one of two lanes closed.
Posted: December 14, 2018, 6:01 am
Location : The A308M westbound between the junctions with the A308 and the M4 . Lane Closures : Lane one will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : From 20:00 on 20 December 2018 to 06:00 on 21 December 2018. Lanes Closed : There will be one of two lanes closed.
Posted: December 13, 2018, 8:10 pm
Location : The M3 eastbound between junctions J3 and J1 . Reason : Emergency roadside drains works are planned. Status : Pending. Schedule : From 22:00 on 17 December 2018 to 05:30 on 18 December 2018. Lanes Closed : All lanes will be closed.
Posted: December 10, 2018, 10:10 pm
Location : The A404 northbound exit slip to the A4155 . Reason : Roadworks are planned. Status : Pending. Schedule : From 21:00 on 17 December 2018 to 06:00 on 18 December 2018. Schedule : From 21:00 on 21 December 2018 to 06:00 on 22 December 2018. Lanes Closed : All lanes will be closed.
Posted: December 10, 2018, 9:10 pm
Location : The M3 eastbound between junctions J4A and J3 . Reason : Roadworks scheme is planned. Status : Pending. Schedule : From 20:00 on 18 December 2018 to 06:00 on 19 December 2018.
Posted: December 10, 2018, 9:07 am
Location : The M3 eastbound between junctions J4A and J4 . Lane Closures : Lanes 1, 2 and 3 will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : From 20:00 on 18 December 2018 to 06:00 on 19 December 2018. Lanes Closed : There will be three of four lanes closed.
Posted: December 10, 2018, 9:07 am
Location : The M3 eastbound at junction J4 . Lane Closures : Lanes 1, 2 and 3 will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : From 20:00 on 18 December 2018 to 06:00 on 19 December 2018. Lanes Closed : All lanes will be closed.
Posted: December 10, 2018, 9:07 am
Location : The M3 eastbound between junctions J4 and J3 . Lane Closures : Lanes 1, 2 and 3 will be closed. Reason : Roadworks are planned. Status : Pending. Schedule : From 20:00 on 18 December 2018 to 06:00 on 19 December 2018. Lanes Closed : There will be three of four lanes closed.
Posted: December 10, 2018, 9:07 am

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