The M32 motorway, linking Bristol to the M4, has been identified as one of the most dangerous and congested roads in England and Wales, according to a recent analysis by tyre specialists Blackcircles, based on government data.
In 2024, the M32 recorded an average of 2.2 collisions per kilometre—more than double the national motorway average of 1 collision per kilometre. This rate ties the M32 with the M25 and the M602 as the highest collision hotspots in the country.
Traffic congestion on the M32 is equally severe. Commuters regularly face long delays, with the motorway averaging 24.9 seconds of delay per vehicle per mile, making it one of the slowest routes nationwide. For comparison, delays on the M1 corridor from London to Leeds are nearly half that, at 12.6 seconds per vehicle per mile.
Blackcircles ranked the M32 as the second most dangerous motorway overall in England and Wales, just behind London’s M25. This ranking factored in daily traffic volumes, collisions per kilometre, average speeds, and delay times. The M32’s high danger rating is partly due to its compact size—about ten times shorter than average—yet carrying some 75,000 vehicles daily, leading to overcrowding and heightened risk.
On the other end of the spectrum, the M45 motorway, which runs through Northamptonshire and Warwickshire, recorded the lowest collision rate at just 0.2 per kilometre, reflecting its much lighter traffic volumes.
The report attributes the majority of motorway collisions to “ineffective observation” by drivers, riders, or pedestrians. Dangerous or reckless driving was the second most common cause, followed by speeding relative to road conditions. Sudden braking and slippery surfaces rounded out the top five causes of accidents on UK motorways.