THE M4 has been ranked the second slowest motorway in the UK according to new figures.

The findings, released today by tracking firm SATRAK, was based on data from 527,000 vehicles over the period of a year to name and shame the most sluggish motorways across the country.

The data covers Britain’s entire 2,173 miles of motorway network.

The worst offender was the M25 which had an average speed of 25.05mph meaning it would take a vehicle nearly five hours to travel just 117 miles, which is the equivalent flight time of a plane travelling from London to Turkey or Greece.

As the main corridor route between London and Wales for millions of drivers every year, the M4, which passes through Swindon and Wiltshire, came in a close second place and on average, the speed many drivers faced at certain intervals came in at 30.46mph.

Dan Walton, MD of SATRAK Vehicle Tracking, said the company hopes the figures give people food for thought.

He added: “The M4 is a major motorway for many of our clients. Linking some of the major towns and cities in the south with London, we could perhaps expect it to be a little speedier.

“That said, however, there have been some improvements in the past five years so hopefully these will continue to make life a little easier for those that travel on it on a daily basis.

“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.”

SATRAK released the figures in response to an announcement in February that stated the average driver will spend 32 hours a year in traffic jams.

The company, which specialises in vehicle security tracking products for businesses and fleets across the country, also compared the slowest cities across the UK with Cambridge coming out on top where motorists face an average speed of just 13.73mph.

Oxford was ranked the tenth slowest city in the UK where the average speed is just 16.49mph whereas the fastest average speeds in cities were found to be in Carlisle (44.7mph), Preston (39.8mph), and Winchester (39mph).