Longest Motorway in UK – M6 Length, Route and Ranking

The M6 is the longest motorway in the United Kingdom, stretching approximately 231 miles from the Midlands to the Scottish border. It forms a vital north‑south corridor for freight and passenger travel, linking major cities and economic hubs. This article explores its exact length, route, ranking among UK motorways, and how it compares with the world’s longest roads.

What is the longest motorway in the UK?

• The M6 is the longest motorway in the UK, spanning approximately 231 miles.
• It is also the oldest motorway, with the first section opening in 1958.
• The M6 connects the West Midlands to North West England and Scotland, continuing as the A74(M).
• The second longest motorway is the M1 (approx. 200 miles), followed by the M4 (approx. 189 miles).
• The UK’s longest motorway is much shorter than the world’s longest motorway (e.g., Pan-American Highway or Australia’s Highway 1).

What are the top 5 longest motorways in the UK?

Beyond the M6, several other motorways form the backbone of the UK motorway network. The M1 runs about 200 miles from London to Leeds, making it the second longest. The M4 stretches 189 miles from London to Pont Abraham in Wales. The M5 travels 162 miles from Birmingham to Exeter, and the M25 orbital around London completes the top five at 117 miles.

What is the second longest motorway in the UK?

The M1 is the second longest, covering approximately 200 miles. It is a major north‑south route that runs from the M25 in Hertfordshire to Hook Moor near Leeds.

What is the third and fourth longest motorway in the UK?

The M4 (189 miles) and the M5 (162 miles) take the third and fourth spots. The M4 serves south Wales and the M5 provides an alternative western route to the South West.

Where is the longest motorway in the UK on a map?

The M6 begins at the Catthorpe Interchange (Junction 19 of the M1) in Leicestershire and heads northwest. It passes near Coventry, Birmingham, Wolverhampton, Stoke‑on‑Trent, the Manchester/Liverpool corridor, Preston, Lancaster and Carlisle before ending at Junction 45 near Gretna, just short of the Scottish border. Beyond that point the road becomes the A74(M), which connects to the M74 towards Glasgow.

What is the longest motorway in Scotland?

The longest motorway in Scotland is the M8, running approximately 60 miles (97 km) from Edinburgh to Glasgow.

What is the longest motorway in Ireland?

In the Republic of Ireland, the longest motorway is the M1, about 50 miles (80 km) from Dublin to the border near Newry.

How does the UK’s longest motorway compare to the world’s longest?

The M6 is very long by UK standards but modest globally. The world’s longest motorway‑style routes, such as the Pan‑American Highway (over 19,000 miles) and Australia’s Highway 1 (about 14,500 miles), dwarf its 370 km. Even within Europe, motorways like the A‑10 in France and the German Autobahn network include stretches far longer than the M6.

When was the M6 motorway built?

1. 1958 – First section opens (Preston Bypass), which later becomes part of the M6.
2. 1960s–1970s – Gradual extension northwards and southwards.
3. 1986 – M6 Toll opens as an alternative to bypass Birmingham.
4. 2008 – Final section between Carlisle and Gretna Green completed, making the M6 continuous from Catthorpe to the Scotland border.

How reliable are the length figures for the M6?

Different sources give slightly different numbers. Below is a summary of what is established and what remains uncertain.

Why is the M6 so important to the UK?

The M6 is not just the longest motorway; it is also one of the busiest. Over 130,000 vehicles travel on it daily, and around 30% of UK road freight moves along this corridor. It serves as a key artery for Scottish produce, Midlands manufacturing, supermarket supply chains, and national logistics.

What do official sources say about the M6?

“The M6 is the longest, oldest and arguably most important motorway in the UK, running 231 miles from Catthorpe to Gretna Green.”

– RAC (2025)

“The M6 motorway is the longest motorway in the United Kingdom. It is located entirely within England, running for just over 230 miles (370 km).”

– Wikipedia – M6 motorway

What is the key takeaway about the longest motorway in the UK?

The M6 is the UK’s longest motorway at about 231 miles (370 km), running from the M1 near Rugby to the Scottish border at Gretna. It is a vital freight and passenger corridor, though its length is modest compared with the world’s longest highways. For a deeper look at the wider network, see our UK Motorway Network Overview.

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