What Motorists Need to Know About the M42 and M6 Closures Planned for August 2026

Drivers who regularly use the M42 and M6 motorways in the West Midlands need to be aware of a series of planned full weekend closures running through to November 2026. The closures are required to allow HS2 contractors to install three enormous railway structures over the motorways, carrying Britain’s new high-speed railway across two of the region’s most heavily used sections of motorway. The next major closure weekend begins at 9pm on Friday 14 August 2026 and runs until 5am on Monday 17 August.

This is not a speculative warning. The closures are confirmed by HS2 Ltd, coordinated with National Highways, and represent some of the most significant planned motorway disruption in England this year. If you use the M42 between junctions 5a and 9, or the M6 near Chelmsley Wood, in either direction, you need to understand which weekends will affect your route and what the signed diversions involve.

What Is Being Built and Why the Motorway Has to Close

HS2 is constructing three separate structures over the M42 and M6 in this section of the route between London and Birmingham. Each structure requires the carriageway below it to be closed when beams or deck sections are being installed, because the load-bearing equipment and the safety exclusion zones around it cannot operate safely with live traffic running underneath.

The first structure is a twin box structure above both carriageways of the M42 near Birmingham Business Park, between junctions 6 and 7. This structure requires four weekend closures to allow engineers to install 175 individual steel beams, each weighing between 56 and 92 tonnes, using a 300-tonne crawler crane.

The second and third structures are two single-track viaducts, each approximately 1,200 metres long, over the M42 and M6 Toll Road near Water Orton. The weekend closures are needed to install the sections of viaduct that bridge the gap between existing piers across the live carriageway.

A fourth structure, a twin-track viaduct over the M6 near Chelmsley Wood, will require a single weekend closure. The M6 closure near Chelmsley Wood is currently scheduled for the weekend beginning Friday 21 August.

The Full Schedule of Closures

HS2 has confirmed the following closure weekends. In each case, the closure runs from 9pm on Friday evening to 5am on Monday morning.

The M42 between junctions 5a and 7 northbound and junctions 6 and 7 southbound was closed on the weekend of 26 to 29 June 2026 for the first beam installation on the Birmingham Business Park twin box structure. A further closure of M42 between junctions 6 and 9 northbound and junctions 7a and 6 southbound took place on the weekend of 24 to 27 July 2026 for the Water Orton viaduct work.

The next confirmed closure is the weekend of 14 to 17 August 2026. This closure covers the M42 and affects traffic in the junctions 6 to 9 northbound corridor. Drivers should plan alternative routes for the full Friday evening to Monday morning window, as there is no guarantee that the closure will be lifted earlier than 5am on Monday even if works complete ahead of schedule.

A further closure is confirmed for the weekend of 18 to 21 September 2026, covering the M6 Chelmsley Wood viaduct installation.

Agnes Usciak, HS2 Ltd’s Senior Project Manager for the works, noted that the works programme had been deliberately consolidated to reduce the impact on motorists, with what originally required nine weekend closures reduced to six through careful coordination of the installation sequence.

The Signed Diversion Route and How Long It Will Take

When the M42 is closed between the affected junctions, National Highways will implement a signed diversion route. Drivers should assume that the diversion will add significant time to their journey. The M42 serves Birmingham Airport, the National Exhibition Centre and Birmingham Business Park, all of which generate substantial traffic at all hours. Weekend diversions in this area can add 45 minutes or more to journey times even when traffic volumes are lower than weekday peaks.

Ian Doust, Head of Network Planning and Development at National Highways, acknowledged that some disruption is inevitable given the scale of the infrastructure being built, and advised drivers to leave extra time for their journeys and use alternative routes if possible. National Highways will operate variable message signs on approach roads ahead of each closure weekend to warn drivers and direct them to the signed diversion.

Drivers approaching from the M40, M6 Toll or A45 who would normally use the M42 to reach the NEC or Birmingham Airport should allow substantial additional time and check the Traffic England website at trafficengland.com for live updates on the closure dates and diversion routes in the days before each closure weekend.

What This Means for Journeys Through the West Midlands

The M42 is one of the most important orbital motorways in England. It connects the M1, M6, M40 and M5 in an arc around the south and east of Birmingham, and acts as a key route for long-distance freight, airport traffic and general through traffic avoiding the city centre. A full weekend closure of any section has network-wide effects, as traffic displaced from the M42 seeks alternative routes on roads that are not designed to carry that volume.

Drivers planning journeys on any of the closure weekends should consider whether their journey can be avoided entirely, rescheduled to avoid the Friday evening to Monday morning window, or routed via a genuinely practical alternative. Checking live traffic information before setting off, and building substantial extra time into journey plans, will make the experience less frustrating.

Freight operators and businesses that rely on reliable delivery windows through the West Midlands corridor should communicate the closure schedule to their logistics teams well in advance. The confirmed closures are known months ahead, and adjusting scheduling to avoid Friday evenings and Monday mornings on the affected weekends is feasible with sufficient planning.

The Bigger Picture of HS2 Progress

The motorway crossings represent some of the most visually dramatic and logistically complex engineering work currently under way on the HS2 route. Construction of the railway between London and Birmingham has involved thousands of workers and hundreds of major engineering interventions, from tunnelling through the Chilterns to constructing viaducts and cuttings through the Midlands countryside.

The M42 twin box structure and the Water Orton viaducts are critical components of the route’s approach to Birmingham. Once complete, they will carry high-speed trains across motorways that were themselves major engineering achievements when built decades earlier.

For drivers navigating the West Midlands over the remainder of 2026, the practical priority is awareness. The next closure is 14-17 August 2026. Plan ahead for that weekend, and check the HS2 Ltd website at hs2.org.uk/hs2-motorway-works for the latest information on all upcoming closure dates and diversion arrangements before travelling.

Sources:

• HS2 Ltd: Notice of M42 weekend closures
• RailAdvent: M6 and M42 motorway closures confirmed for HS2 work until November
• HS2 Ltd: Major HS2 motorway works planned across the West Midlands in 2026