What are Britain's busiest roads, and where is traffic growing?
The M25 between junctions 13 and 14 carried an estimated 209,610 vehicles a day in 2025, Britain's busiest stretch. The busiest roads and the fastest-growing ones.
Roads
209,610
estimated vehicles a day on the M25 at J13 to J14
- 209,610 vehicles a day (estimated) on the M25 between J13 and J14
- 145,590 vehicles a day on average along the whole M25
- 8.59bn vehicle miles on the M6, the most of any road
- +1.2% traffic in Great Britain in 2025 compared with 2019 (DfT)
The busiest roads in Britain carry well over 100,000 vehicles a day. We compared traffic on 999 motorways and A-roads to find the busiest roads, the busiest single stretch, and the roads where traffic has grown most since before the pandemic.
All road figures are for 2025, from the Department for Transport’s count points, and cover Great Britain, counting vehicles a day in both directions. You can see every road on our Britain’s busiest roads page.
What is the busiest stretch of road in Britain?
The M25 between junctions 13 and 14 in Surrey carried an estimated 209,610 vehicles a day in 2025. That’s the highest of any section of road half a mile or longer in Great Britain.
What 209,610 vehicles a day looks like
That works out at about 146 vehicles a minute, around the clock. It’s 44% more than the average along the whole M25, which is itself Britain’s busiest road.
The link is in Surrey, near Heathrow Airport. The M25 traffic and busiest junctions page shows the flow on every link.
DfT didn’t count this link in 2025, so its figure is an estimate based on earlier counts and local trends. Junctions 15 to 16, also estimated, were almost as busy at 208,946 vehicles a day, only 0.3% fewer.
The busiest sections on other motorways
The busiest link on the M6 was junctions 20 to 21, with 187,521 vehicles a day. On the M56, junctions 3 to 4 carried 179,634.
Some very short slip roads and spurs post big numbers too, but they aren’t main routes. We leave them out of the busiest sections so the comparison stays fair.
Which roads are the busiest in Britain?
The M25 is Britain’s busiest road, with an average of 145,590 vehicles a day along its 118.4 miles. The M60 around Manchester is second at 131,422 and the M1 third at 115,234.
The busiest motorways and A-roads
These figures are an average along the whole road, weighted by the length of each link. That’s why a short, packed road can rank above a long one with quieter stretches.
| Road | Route | Miles | Vehicles a day | Busiest section (vehicles a day) | HGV share | Change since 2019 |
|---|---|---|---|---|---|---|
| M25 | Kent to Thurrock | 118.4 | 145,590 | J13 to J14: 209,610 | 11.4% | -0.7% |
| M60 | Bury to Stockport | 37.8 | 131,422 | J27 to J1: 154,520 | 6.2% | +5.7% |
| M1 | Barnet to Leeds | 203.4 | 115,234 | J11 to J11A: 160,205 | 13.2% | +0.6% |
| M27 | Hampshire to Portsmouth | 32.1 | 105,676 | J3 to J4: 136,437 | 5.3% | +0.2% |
| M56 | Stockport to West Cheshire | 37.5 | 104,912 | J3 to J4: 179,634 | 8.2% | +3.8% |
| A282 | Thurrock to Kent | 7.4 | 107,017 | A206 to A296/A225: 132,850 | 14.6% | +0.1% |
| A406 | Hounslow to Newham | 28.5 | 87,764 | A104 to Southend Road: 149,848 | 4.3% | -4.4% |
| A720 | Edinburgh to East Lothian | 14.0 | 68,177 | M8 to A71: 93,585 | 5.3% | +4.3% |
Ring roads dominate the top
The two busiest roads, the M25 and the M60, are both ring roads. The M60 is only 37.8 miles long, and its traffic is up 5.7% on 2019, more than any other road in the top five.
The M1 is the busiest of the long-distance motorways. Its busiest link, junctions 11 to 11A, carried 160,205 vehicles a day.
Related: M60 Manchester ring road traffic
What is the busiest A-road in Britain?
The A282 at Dartford is the busiest A-road, with 107,017 vehicles a day in 2025. It’s busier than every motorway except the M25, M60 and M1.
The Dartford Crossing approaches
The A282 is only 7.4 miles long, carrying M25 traffic across the Thames between Thurrock and Kent at the Dartford Crossing.
HGVs were 14.6% of its traffic, the highest lorry share of the busy roads in the table above.
London and Edinburgh’s ring roads
The A406 North Circular is second, with 87,764 vehicles a day. Its busiest section, from the A104 to Southend Road, carried 149,848.
The A720 Edinburgh City Bypass is third with 68,177 vehicles a day. Unlike the North Circular, its traffic is up 4.3% on 2019.
Which motorway carries the most traffic in total?
The M6 carries the most traffic of any road in Britain: 8,587 million vehicle miles in 2025. The M1 is a close second at 8,555.1 million, just 31.9 million behind.
Why the M6 beats the M25
Vehicle miles count every vehicle multiplied by the distance it travels. The M6 is 246.4 miles long, more than twice the M25, so it racks up more in total even with fewer vehicles a day.
On our figures, the M6 alone accounts for about 11.9% of all motorway traffic in Great Britain. The M6, M1 and M25 together carry about 32.6%.
| Road | Miles | Vehicles a day | Vehicle miles, 2025 (millions) | Change since 2019 |
|---|---|---|---|---|
| M6 | 246.4 | 95,479 | 8,587.0 | +9.0% |
| M1 | 203.4 | 115,234 | 8,555.1 | +0.6% |
| M4 | 196.5 | 91,647 | 6,573.1 | -0.8% |
| M25 | 118.4 | 145,590 | 6,291.8 | -0.7% |
| M5 | 165.9 | 97,573 | 5,908.4 | +6.4% |
Lorries on the motorways
HGVs made up 14.1% of traffic on the M6. Among motorways of 20 miles or more, the M180 had the highest share at 25.2%.
Across all motorways and A-roads, cars and taxis were 75.1% of vehicle miles, vans 17.0% and HGVs 6.7%.
Where is traffic growing fastest?
The A375 in Devon has grown fastest since 2019, with traffic up 27.0% by 2025. We only compare roads of 10 miles or more where at least 70% of the road can be measured like for like.
The fastest-growing and fastest-falling roads
Of the 549 roads that meet those rules, 220 carry more traffic than in 2019 and 327 carry less. Some of the biggest risers are quiet roads, such as the A713 with 3,242 vehicles a day, where small changes in traffic make big percentages.
| Road | Where | Miles | Vehicles a day, 2025 | Change 2019 to 2025 |
|---|---|---|---|---|
| A375 | Devon | 10.0 | 8,321 | +27.0% |
| A713 | South Ayrshire to Dumfries & Galloway | 48.8 | 3,242 | +25.9% |
| A161 | Nottinghamshire to East Riding of Yorkshire | 30.1 | 3,616 | +20.4% |
| A144 | Suffolk | 14.2 | 5,981 | +18.2% |
| A477 | Carmarthenshire to Pembrokeshire | 28.5 | 12,693 | +17.9% |
| M6 (top comparable motorway) | Leicestershire to Cumberland | 246.4 | 95,479 | +9.0% |
| A503 (biggest fall) | Camden to Waltham Forest | 10.0 | 16,233 | -18.0% |
Motorways growing and shrinking
Of the motorways we can compare, the M6 grew most, up 9.0% since 2019. The M25, Britain’s busiest road, is slightly down at -0.7%.
The biggest fall of all was on the A503 in north London, down 18.0%. The data shows the change but can’t tell us why it happened.
Is traffic back above pre-pandemic levels?
Yes, just. The Department for Transport puts traffic in Great Britain at 342.6 billion vehicle miles in 2025, 1.2% above 2019 and 1.9% up on 2024.
National traffic in 2025
DfT’s road traffic estimates for 2025 cover all motor vehicles on all roads. Motorways carried 71.9 billion vehicle miles, 2.0% more than in 2019, according to DfT’s traffic by road type figures.
DfT also notes that motorways and A-roads carry 65% of all traffic, despite making up 13% of road length.
| Traffic in Great Britain (DfT) | 2025, billion vehicle miles | Change since 2019 |
|---|---|---|
| All motor vehicles | 342.6 | +1.2% |
| Motorways | 71.9 | +2.0% |
| Vans | 58.8 | +10.0% |
Vans are behind much of the growth
DfT’s headline figures show van traffic 10.0% above 2019. Car traffic was 0.2% below 2019 and lorry traffic 5.1% below.
Road-level growth on this page is measured at count points present in both years, so it isn’t the same measure as DfT’s national totals. The road figures come from DfT’s count point data, and our methodology page explains how we use it.
FAQs
What is the busiest road in Britain?
The M25, which averaged 145,590 vehicles a day along its 118.4 miles in 2025. The M60 around Manchester was second with 131,422.
What is the busiest stretch of road in Britain?
The M25 between junctions 13 and 14 in Surrey, near Heathrow, with an estimated 209,610 vehicles a day in 2025. That's about 146 vehicles a minute, day and night.
What is the busiest A-road in Britain?
The A282 at the Dartford Crossing, with 107,017 vehicles a day in 2025. The A406 North Circular was next with 87,764.
Which road carries the most traffic in total?
The M6, with 8,587 million vehicle miles in 2025, just ahead of the M1 at 8,555.1 million. At 246.4 miles, it's the longest motorway in our data.
Is traffic back to pre-pandemic levels?
Yes. The Department for Transport puts 2025 traffic in Great Britain at 342.6 billion vehicle miles, 1.2% above 2019 and 1.9% above 2024.
Which road has grown fastest since 2019?
Among roads of 10 miles or more with comparable counts, the A375 in Devon, where traffic rose 27.0% between 2019 and 2025. On motorways, the M6 grew most, by 9.0%.
Which motorway has the most lorries?
Among motorways of 20 miles or more, the M180, from Doncaster to North Lincolnshire, where HGVs were 25.2% of traffic in 2025. Across all motorways and A-roads, HGVs were 6.7% of vehicle miles.
How is traffic on each road measured?
From DfT count points, using manual and automatic counts. Links that weren't counted in a given year are estimated from earlier counts and local traffic trends.
About the author
The UK Motoring editorial team analyses official motoring data and checks every figure against its source before it is published.
