M40/M42 interchange: smart motorway

The M40/M42 interchange is often congested at peak times, affecting both local journeys and long distance traffic between London and Scotland. This interchange upgrade will reduce congestion and delays, improving journey times for motorists. It will also support major new developments in Birmingham, Solihull and the Black Country, boosting economic growth and job creation.

Start date Started

End date 2023-24

Cost £133 million - £312 million

Latest updates

26 April 2021
Final phase of overnight survey work starts in May

In early May we’ll start the final phase of our overnight survey work to gather information which will inform the design of this vital interchange upgrade scheme.

We’ll be working:
- between M42 junctions 3 and 3a from 4 May to 27 May
- between M42 junction 3a and M40 junction 16 from 1 June to 17 June
- between M42 junctions 3a and 4 from 18 June to 23 July
What are we doing?

We’ll carry out a number of different surveys on both carriageways. These will include drilling carriageway core samples, excavating small trial holes and ecology inspections.

We’ll work overnight, when the road is at its quietest.

How will the survey work affect motorists?

To safely carry out the surveys we’ll need to close some lanes, in 4km sections at a time, but will keep one lane open on each carriageway while we work (Monday to Saturday between 9pm and 6am). We’ll take a ‘traffic count’ before we close the lanes and if the traffic levels are too high, we’ll delay the work until they reduce.

All lanes will be open as usual during the daytime.

We’ll also need to close the following slip roads overnight:
- M40 to M42 northbound link road from 14 June to 25 June
- M42 junction 3a to M42 northbound link road from 28 June to 25 July
- M42 to M40 southbound link road from 12 July to 20 July
We’ll put in place clearly signed diversion routes to the next junction when the slip roads are closed.

We apologise for any inconvenience this work may cause and advise everyone travelling through the area to allow extra time for journeys.

Please note these dates and times may be subject to change due to poor weather or for operational reasons.
26 February 2021
An update on our survey work

On 1 March we’ll start overnight survey work on the M42 between junctions 3a and 4, to gather information which will inform the final design of this vital interchange upgrade scheme.

What are we doing?

We’ll carry out a number of different surveys on both carriageways. These will include checking drainage systems and existing buried services locations (including electrical and telecommunications cables), drilling carriageway core samples and ecology inspections. We’ll also clear vegetation in some isolated areas to help us safely carry out the surveys.

We’ll work overnight, when the road is at its quietest, for 6 weeks.

How will the survey work affect motorists?

To safely carry out the surveys, we’ll need to close some lanes, in 4km sections at a time, but will keep one lane open on each carriageway while we work (Monday to Saturday between 9pm and 6am). We’ll take a ‘traffic count’ before we close the lanes and if the traffic levels are too high, we’ll delay the work until they reduce.

All lanes will be open as usual during the daytime.

We’ll also need to close the following slip roads overnight from Monday to Saturday between 9pm and 6am:
- M40 J16 southbound exit slip road on 1, 2 and 3 March 2021
- M40 J16 northbound entry slip road on 4 and 5 March 2021
- M42 J3 southbound exit slip road every night between 8 and 12 March 2021
- M42 J4 southbound entry slip road every night between 15 and 19 March 2021
- M42 J4 northbound exit slip road every night between 22 and 26 March 2021
Please note these dates and times may be subject to change due to poor weather or for operational reasons.

Diversion routes will be clearly signed but please note the diversion through Hockley Heath is only for traffic originating in Hockley Heath.

We apologise for any inconvenience this work may cause and advise everyone travelling through the area to allow extra time for journeys.
13 January 2021
Ongoing survey work

Since November 2020, we’ve been carrying out a number of different surveys on both carriageways between M42 junction 3 and 3a. On the 18 January, we’ll be moving onto the section between the M42 junction 3a and M40 junction 16. We’ll need overnight lane closures from 9pm and 6am to carry out the surveys safely.

We’ll also need close the following slip roads overnight from 9pm and 6am:
- M42 northbound to M42 northbound link at junction 3a - 5, 6, 7, 8 and 11 January 2021
- M42 southbound to M42 southbound link at junction 3a - 12, 13, 14,15 and 18 January 2021
- M40 northbound to M42 northbound link at junction 3a - 15, 16, 17, 18,19, 20 and 21 February 2021
- M42 southbound to M40 southbound link at junction 3a - 22, 23, 24, 25 and 26 February 2021
- M40 J16 northbound entry slip road - 17 and 18 February 2021 and 3, 4 and 5 March 2021.
- M40 J16 southbound exit slip road closed – 1, 2, 3, 4 and 5 February 2021.
Please note that these dates may be subject to change
27 October 2020

Survey work

Over the next few months, we’ll carry out a number of different surveys. We’ll also need to carry out vegetation clearance in some isolated places to help us access the areas safely while we carry out the surveys. We’ll be working hard to keep any disruption to a minimum, but you may hear noise from the vegetation clearance or drilling if you live close by.

To carry out the surveys safely, we’ll need to close some lanes overnight from Monday to Saturday between 9pm and 6am. We will keep one lane open. We’ll carry out a ‘traffic count’ before we close the lanes and if traffic levels are too high, we will delay the work until traffic levels are suitable. If you’re travelling through the area, please allow extra time for your journeys

During January and February 2021, we’ll need some overnight closures of the M42 junction 3a link roads in. During these closures, we’ll divert road users to the next junction to return straight back to continue their journey.
21 August 2020

Scheme to be delivered by 2023-24

As we deliver this important road upgrade, we are conscious of the need to keep the region moving. We will coordinate our work with HS2 and the Commonwealth Games to minimise disruption to the network and we are currently finalising our work programme on this basis. We will deliver the scheme by 2023-24, but now expect to start the main construction work slightly later than originally planned.

See more updates

Project information

Over the last year, we have been gathering information about the road and the areas that surround it to develop the design for the M40/M42 Interchange smart motorway project.

Our proposed regulations include the introduction of variable mandatory speed limits to the M40 / M42 Interchange, including slip roads, between M42 J3 and J4 and M40 J16 as part of the M40 / M42 Interchange Smart Motorway Scheme.

Following the consultation period, we will produce a report which will provide a summary of the responses, the decision whether to proceed or to modify the proposals and allow us to respond to any comments made.

The M40/M42 interchange is very important for local traffic and forms an important link for long distance traffic travelling between London and Scotland.

Congestion already occurs frequently at peak times at the interchange.

This scheme aims to: