How much traffic actually uses the M1, where it is heaviest, and which stretches carry the freight. These pages use the Department for Transport’s own road traffic counts for 2025 — the same figures used for national transport planning — covering 42 stretches of M1 mainline.

The M1 is not one road, and the numbers show it

The busiest stretch carries 159,683 vehicles a day and the quietest 66,698. On one stretch nearly one vehicle in five is a lorry; on another it is closer to one in twenty-five. Averages hide all of that, which is why these pages give the figure stretch by stretch.

Where to start

How Busy Is the M1, Junction by Junction?
Every measured stretch of the M1 mainline, ordered busiest to quietest, with cars and lorries separated out.

M1 Lorry and Freight Traffic
Where heavy goods vehicles make up nearly a fifth of everything on the road, and where they barely register.

What these numbers do not tell you

Annual average daily flow counts how many vehicles use a stretch. It does not measure how slowly they travel. A wide four-lane stretch can carry 150,000 vehicles a day and keep moving, while a narrower one carries far fewer and crawls. Busiest is not the same as worst, and this page does not claim it is. For what is happening on the M1 right now, see the latest M1 traffic news.