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What are the biggest and best roads in the UK?

Two sheep walking in the road

The UK is home to hundreds of A-roads, B-roads, motorways and more, so if you’re not using SatNav to get you from A to B (literally) it can be easy to get confused or lost while on your travels. It doesn’t help that these roads don’t have the most inspiring of names either. Letters and numbers are hardly the most memorable, so you can’t be blamed for not remembering which one is which.

With so many roads and motorways spanning the length and breadth of the country, it got us thinking… if their names are not the most interesting, let’s find some things that might make them a bit more memorable. In our latest blog, we’re going under the hood of the UK’s roads and motorway networks, looking at which ones are the longest, widest and some other fun facts in between.

Motorways in the UK

UK motorways are an essential part of the country’s road network, connecting cities and towns and enabling efficient transport of goods and people. The first full-length motorway in the UK, the M1, opened in 1959 and, since then, the network has expanded to over 2,300 miles today. Motorways, or M-roads, are typically the biggest roads in the country width-wise, usually consisting of more than two lanes in either direction. 

Motorways are designed to be high-speed roads with restricted access, meaning that only designated motor vehicles are allowed to use them – there are no intersections or crossings on motorways. This makes them safer and more efficient than other types of roads. Although they are rarer, accidents on motorways can be more severe than on other roads due to the high speeds.

To ensure safety, there are a number of rules and regulations that drivers must follow when using motorways. For example, the speed limit is typically 70mph (although this can be reduced in certain areas, for example, near roadworks). Drivers also need to keep a safe distance from the vehicle in front and signal before changing lanes.

What is the difference between motorways and A-roads?

UK A-roads are major roads that typically connect cities and towns. ‘Primary’ A-roads connect the main cities, while ‘non-primary’ A-roads connect the smaller towns and villages. There are tens of thousands of miles of A-roads in the UK, ranging from single-carriageway roads to dual-carriageways with multiple lanes.

If you see blue signs, you are on or approaching a motorway. But, if the signs are green or another colour, you’re likely on an A-road, B-road, or in a city. Motorways will always have a hard shoulder, and pedestrians, bicycles and some small vehicles are not allowed on them. Some A-roads will allow bicycles and small vehicles unless stated otherwise. The speed limit on A-roads is more likely to vary than motorways, often anywhere between 30 mph and 70 mph.

What is the longest motorway in the UK?

Aerial top view of road traffic

The M6 is the longest and biggest motorway in the UK, at 232 miles (373 kilometres). It connects major cities such as Birmingham, Liverpool, Manchester and Glasgow, making it a vital route. It’s considerably longer than the next longest motorway, the M1, which is about 193 miles (311 kilometres).

The M6 first opened in 1958 and has undergone numerous upgrades and improvements over the years, with the most recent being the addition of the Smart Motorway system, which has since helped to alleviate some congestion issues. Despite being open slightly longer than the M1 (the UK’s first full-length motorway), the M6 was originally a bypass that ran by Preston, and not a motorway.  

It is home to over a dozen different service stations and over 40 junctions, so you’re not short of options to take a break should you be making the trip from top to bottom or vice versa. What’s more, almost all of these service stations currently have charging points for electric vehicles, helping to make the M6 an eco-friendly route. To learn more about electric cars and what it’s like to own one, head over to our all-you-need-to-know guide.

Being the longest motorway in the UK, the M6 can get quite busy, so some extensions of it have been developed. You may already be aware of a route named the M6 toll. This is just north of Birmingham and it connects M6 Junction 3a at the Coleshill Interchange to M6 Junction 11A at Wolverhampton. It acts as an expressway and it requires payment to use which can be via debit card, credit card or a fuel card. If you do need to access the M6 toll, you can learn more about the payment methods at

The M6 toll is only 27 miles (43.5 kilometres), which is nothing compared to these five motorways in the UK that, along with the M6, clear the 100-mile mark:

The M1: 193.5 miles (311.4 kilometres)

The one that started it all: Britain’s first full-length motorway, opened in 1959. Known as the Yorkshire-London Motorway, this classic road goes all the way from London to Leeds. Fun fact: In the early days of the M1, it had no speed limit. 

The M4: 189 miles (304.2 kilometres)

The M4 motorway is probably most famous for being the link road between Barry Island and Essex in the iconic Gavin and Stacey TV series. Also referenced in the popular TV show is one of the M4’s favourite service stations, Leigh Delamere, which sits between Junction 17 and Junction 18. At 189 miles from London to just west of Swansea, there’s a whole lot of M4 to enjoy. The M4 is also home to the Prince of Wales Bridge (formerly known as the Second Severn Crossing) which spans the River Severn. It used to have a toll but it is now no longer in use, meaning you can use the bridge connecting England and Wales at no cost.

Junction 15 on the M4 actually connects to the next motorway on this list below…

The M5: 162.9 miles (262.2 kilometres)

The classic holiday road acting as the gateway to holiday-haven Cornwall in the south of England, the M5 motorway comes in at a respectable length, just shy of 163 miles. The first on our list to bypass London entirely, this one is strictly on the west-side, running from just west of Birmingham all the way down to Exeter.

The M25: 117 miles (188.3 kilometres)

Otherwise known as the London Orbital Motorway – or, the big, old ring road we love to hate. Unlike the M5, this one can’t seem to get enough of London, encircling the capital city entirely. One of the busiest roads in the UK, often plagued with floods and traffic jams, the M25 is the problem child of the motorway world… Fun fact: the M25 is the second longest ring road in Europe.

The M62: 107 miles (172.2 kilometres)

The great northern lifeline, the M62 connects the cities of Liverpool and Hull and is home to one of the best-known sites on the British motorway network: the 18th Century farmhouse, Stott Hall Farm, which sits on an island between the lanes. Some believed that the M62 motorway was built around the farmhouse because the owners wouldn’t sell it, but in fact, it was because of a geological issue. Another fun fact: at 1,221 feet above sea level, the section of the M62 that runs through Windy Hill is the highest point of a motorway in the UK.

So, the M6 and M1 are both by far Britain’s longest motorways, but neither of them a close to being the longest road…

What is the longest road in the UK?

The longest road in the United Kingdom is actually the A1 road, which connects London to Edinburgh. The A1 stretches over 400 miles, and some parts of it have been upgraded and are now classed as ‘motorway’, or ‘A1(M)’. It passes through several major cities such as Leeds and Newcastle. Previously known as the ‘Great North Road’, it was originally built by the Romans and used as a major trade route. If you travel the whole length of the A1, you can expect to see a variety of different landscapes, from the busy streets of London to the hills of the north, and even a few national parks.

Contrary to what some believe, the A5, although it continues through two countries, is not the longest road in the country. It distances only about 243 miles (391 kilometres).

The longest UK roads

The forth road bridge in Scotland

2. The A38: 309.8 miles (498.6 kilometres)

The A38 runs from Cornwall to Nottinghamshire and was first designated in 1922, initially running from Plymouth to Derby.

3. The A30: 284 miles (457.1 kilometres)

Similarly to the A38, the A30 also runs from Cornwall (Land’s End), but heads in the direction of London.

4. The A6: 282 miles (453.8 kilometres)

The A6 goes from Bedfordshire to Cumbria, and part of it was used in the 18th Century, making it technically the oldest road on this list.

5. The A9: 273 miles (439.4 kilometres)

The A9 is actually the longest road in Scotland, running from Falkirk to Scrabster Harbour on the north coast.

Where is the longest straight road in the UK?

The A15 between Scampton and the M180 is regarded as the longest straight road in the UK, continuing for about 18 miles without a turn. However, this is no excuse to relax! Drivers need to always stay alert on the road ahead and surrounding vehicles.

What is the longest street in London?

This would be Rotherhithe Street in Southwark, London. At around 1.5 miles, it wouldn’t be uncommon to drive from one end to the other. Although this might not sound too long, this is actually a very long street in comparison to the rest of London, considering the congested nature of the city. This street alone is home to St Mary’s Church, Surrey Docks Farm and Nelson House.

Whilst you’re cruising down the long and short roads of London, be sure you aren’t unknowingly heading towards a congestion charge.

Where is the longest road tunnel in the UK?

Tunnel entrance

Love them or hate them, road tunnels are all over the UK and provide a much faster alternative to going over, under or around hills, mountains and rivers. The longest road tunnel in the UK is the Queensway tunnel in Liverpool, which is about 2 miles in length and currently requires a £2 toll for cars to use. The tunnel was originally constructed just for the railway line to pass under the Mersey in the 1880’s. The road tunnel eventually opened in the 1930’s after complaints about queues of vehicles at the Mersey Ferry terminal.

Also, it was one of the first tunnels to use a ventilation system that operates on the principle of displacement ventilation – a system that uses fans to draw fresh air into the tunnel through airshafts and exhausts the stale air through other shafts. It is estimated that around 40,000 vehicles pass through the tunnel every day, making it a vital link between Liverpool and the Wirral. Today, the railway, tunnel and ferries are all still in use over and under the Mersey river.

What is the widest road in the UK?

The notorious M25 hosts the widest public road in the UK, with some parts of it stretching to 6 lanes wide. This can be found between junctions 14 and 15 near Heathrow to allow for traffic to flow to and from the airport. The M25 also used to be the longest ring road in Europe at 117 miles (188 kilometres), but that title now belongs to the Bundesautobahn 10 that surrounds Berlin at 122 miles (196 kilometres) long.

But, which is the best road in the UK?

Shieldaig in Scotland

What makes a road a good road? Is it the scenery? The difficulty? The smoothness of the tarmac? The answer to this may vary for each driver. This question was recently put to the public in a recent survey by National Geographic, with responses from around 2,000 British motorists.

The route crowned as the best in this study was the North Coast 500 route which starts and ends at Inverness Castle in Scotland. Although not technically a road but a series of roads, this route really does take you around some of the best scenery Scotland has to offer, from vast mountains to flowing rivers and beautiful beaches, with plenty of great places to visit along the way. To get the full experience, it is widely recommended for visitors to travel the entirety of the route which is just over 500 miles (830 kilometres) long, so it will take you around 5-7 days if travelling by car. Some people have cycled and even walked the length of the route, but that isn’t for the faint-hearted!

If you’re interested in visiting, you can learn more on the official NC500 website.

Preparing for long journeys

Before heading on holiday, or any other reason, it’s important to make sure your car is prepared for the long journey. This includes selecting the best route, vehicle health checks, safety checks and having the best cover. Check out Warrantywise’s Top 4 Tips To Prepare Your Car For a Long Journey before you set off.

The average UK driver travels 6,800 miles on these roads and motorways each year. That’s a lot of miles! Adding those kind of miles puts motorists at increased risk of part failure. With this in mind, it’s worth considering the added protection of a car warranty for complete peace of mind. Get an extended car warranty quote to suit your vehicle.


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