A new report by vehicle tracking company Satrak has revealed the slowest motorways in Britain.

After analysing data from 527,000 vehicles over the period of a year, the most sluggish motorways have been highlighted using average speeds of the vehicles using them.

Although one of the most important motorways in the UK, the M25 was highlighted as the slowest, with speeds averaging at just 25 mph. This is almost half the average speed of the M602, which found itself in tenth place at 48 mph.

The ten slowest motorways in Britain are as follows:

Also analysed were the slowest cities in Britain, which took data from 3,345,025 vehicles over the same period of time.

After measuring the data, Cambridge was found to be the slowest city in Britain with average speeds totalling a mere 13 mph.

None of the top ten slowest cities exceeded 20mph. The slowest cities are as follows:

The fastest average speeds in cities were found to be in Carlisle (44.7 mph), Preston (39.8mph), and Winchester (39 mph).

Dan Walton, MD of Satrak Vehicle Tracking, said: “It’s little surprise to find that the M25 is in fact the slowest motorway. We undertake work throughout the country and usually find the M25 to be the most cumbersome, and our data provides evidence for that.

“I’ve heard of tailbacks stretching 12 miles in my time there so it’s of little surprise to me. It’s nice to see that people are taking care in many of our cities however, as these places are often busy and above all are not environments for speeding.”