The UK's biggest motorways explained
The UK's motorway network is built around a handful of major routes. The M6 is the longest at around 232 miles, followed by the M1 and the M4. The M25 and M60 are orbital roads ringing London and Manchester. Here is what each of the biggest motorways does and where it runs.
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The M6: the UK's longest motorway
The M6 is the longest motorway in the UK, running around 232 miles from the M1 at Catthorpe in the Midlands up to the Scottish border near Gretna. It is the main road artery between the North West, the Midlands and Scotland.
It passes major cities including Birmingham, Stoke, Manchester and Carlisle, and carries enormous volumes of freight and traffic. Its busiest sections around Birmingham are among the most congested in the country, which is why the parallel M6 Toll was built to relieve them.
The M1: London to the North
The M1 is the UK's second-longest motorway at around 193 miles, running from London up to Leeds, where it meets the A1(M). As Britain's first full-length inter-urban motorway, opened from 1959, it is also one of the most historically important.
It connects London with the East Midlands and Yorkshire, passing Luton, Northampton, Leicester, Nottingham and Sheffield. For decades it has been a backbone of north-south travel and remains one of the busiest routes in the country.
The M4: London to South Wales
The M4 runs around 189 miles from West London westward to near Swansea in South Wales, making it the main route between England and South Wales. It crosses the Severn into Wales and continues past Cardiff and Swansea.
It links Heathrow, Reading, Bristol, Newport and Cardiff, and the corridor it follows is so associated with technology businesses that it is often called the "M4 corridor". It is the principal road connection for much of South Wales to London.
The M62: coast to coast
The M62 is a trans-Pennine motorway of around 107 miles, running coast to coast from Liverpool in the west to Hull in the east, by way of Manchester and Leeds. It is one of the highest motorways in England as it crosses the Pennines.
It is the main east-west route across northern England, connecting two coasts and several major cities. Its exposed Pennine section is known for severe weather, and a famous farmhouse sits between the carriageways at its highest point.
The M25: the London orbital
The M25 is the orbital motorway that encircles Greater London, running around 117 miles in a near-complete loop. It is one of the busiest motorways in Europe and effectively defines the boundary of Greater London for many purposes.
Rather than going from one place to another, the M25 connects the motorways and major roads that radiate out of London, letting traffic move around the capital rather than through it. Its busiest sections see very heavy congestion, and much of it has been upgraded to a smart motorway.
The M60 and M61: around Manchester
The M60 is Manchester's orbital motorway, a ring road of around 36 miles that circles the city. It was created in 2000 by joining together existing motorways around Manchester into a single orbital route, much as the M25 rings London.
The M61 connects the M60 near Manchester to the M6 near Preston, running around 21 miles via Bolton and Chorley. Together with the M62, these motorways form the dense network that moves traffic around and between the cities of the North West.
Other major UK motorways
Beyond the biggest routes, several other motorways carry huge volumes of traffic and are worth knowing. The M5 runs from Birmingham down to Exeter, the main route to the South West and a summer holiday artery. The M40 provides a second route between London and Birmingham, alongside the M1.
In the Midlands, the M42 and M6 Toll help traffic around the heavily congested Birmingham area. Further north and in Scotland, the M8 links Edinburgh and Glasgow as one of the busiest motorways in Scotland, while the M74 continues the route south towards the M6 and England. Around London, the M3, M20, M11 and M23 radiate out to the south coast, the Channel ports, Cambridge and Gatwick respectively. Together with the major routes, these make up the core of the network that connects the UK's cities, ports and airports. Each has its own character and pinch points, but they all share the same rules of the road, so the skills that keep you safe on one apply equally on the next. Planning your route in advance, and knowing which major motorways your journey uses, makes a long trip far less stressful.
How motorways are numbered
The UK's motorway numbers are not random. They broadly follow the same zonal system as A-roads, radiating out from London and Edinburgh, which is why the M1 heads north from London and the numbers increase roughly clockwise.
Knowing the major routes helps you plan and understand journeys across the country. Whichever motorway you are on, the same rules apply: our guide to the motorway driving rules covers lane discipline, smart motorways and breakdowns, and on long drives it is worth knowing the signs of driving tired.
Frequently asked questions
What is the longest motorway in the UK?
The M6 is the longest UK motorway at around 232 miles, running from the M1 at Catthorpe in the Midlands to the Scottish border near Gretna. It is the main route linking the North West and the Midlands with Scotland.
How long is the M25?
The M25 is around 117 miles, forming a near-complete loop around Greater London. It is one of the busiest motorways in Europe and connects the major roads radiating out of London so traffic can move around the capital rather than through it.
Which motorway goes from London to Wales?
The M4 is the main route from London to South Wales, running around 189 miles from West London to near Swansea. It crosses the Severn into Wales and links Reading, Bristol, Newport, Cardiff and Swansea.
What is the difference between the M25 and the M60?
Both are orbital motorways: the M25 rings Greater London at around 117 miles, while the M60 rings Manchester at around 36 miles. Each connects the radial motorways and roads around its city rather than running between destinations.
Which motorway crosses the Pennines?
The M62 is the trans-Pennine motorway, running coast to coast from Liverpool to Hull via Manchester and Leeds, around 107 miles. It is one of the highest motorways in England and its Pennine section is known for severe weather.
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