These top 10 lists will be very interesting to petrol-heads who are enthralled by the sound of an engine revving and its exhaust fumes.

Alfa Romeo made it a point to let drivers know which UK tunnels offer the best acoustics for enjoying the motor’s sound.

The ‘Sound Tunnel Index’ named the 658-metre long Penmaenbach tunnel in North Wales the best in the country – find out which others made the list.  

REVEALED! Italian car maker has conducted its own scientific experiment to discover which UK tunnels are best for petrol heads to enjoy the sound of their cars. Read the top 10 below...

REVEALED! Italian carmaker has carried out its own research to determine which tunnels are the most suitable for petrol heads in order to have their cars sound great. Check out the Top 10… 

Italy’s car manufacturer has made this index scientific by teaming up with Sandy Brown (a leading acoustic consultant), to measure and capture the noise quality inside the Stelvio Qaudrifoglio SUV as it travels through the UK tunnels.  

The consultancy – which has worked with the Royal Albert Hall to improve its acoustics – used the brand’s 510hp 2.9-litre V6 Bi-Turbo performance car to drive through each tunnel in its ‘Dynamic’ mode, which enhances the exhaust sound. 

In order to capture all the effects of exhaust and engine, the passenger windows were closed.  

To determine the best tunnels, the noise inside the vehicle was measured using a sound meter in the front passenger seat.

Sandy Brown’s associate Richard King stated that: “The size and shape of tunnels as well as their length and speed have an effect on how loud you can hear the traffic. 

A combination of the objective analysis using the recorded data and the subjective scores provided by the vehicle’s acoustic specialists was used to form the top 10.

The following is a listing of the 10 most dangerous road bridges.

10. Tyne Tunnel, Durham (A19)

Length: 1,700 metres

Speed limits 30mph

 Obsolete measurement 10th

Subjective ranking 10th

Acoustic experts said the rectangular shape of the Tyne tunnel didn't do much for the car's engine and exhaust sound

According to experts, the Tyne tunnel’s rectangular form didn’t help the car’s exhaust and engine sound.

The Tyne Tunnel is a pair of two-lane tunnels that run under the River Tyne in North East England and is the first toll tunnel in this list, costing £1.90 for car drivers to use.

According to acoustic specialists, the one-way system was the most notable feature, however, it was downgraded for high vehicle traffic.

Its rectangular profile didn’t make the best of the Alfa Romeo Stelvio’s engine and exhaust sounds. 

9.  Limehouse Link Tunnel, Poplar (A1203)

Length: 1,100 metres

Speed limits 30mph

 Obsolete measurement 6th

The Limehouse Link tunnel is a 1.1-mile tunnel in East London on the A1203 road and links to Canary Wharf in London Docklands

Limehouse Link is an East London tunnel measuring 1.1 mi. It runs on the A1203 road. This tunnel connects with Canary Wharf, London Docklands.

Sandy Brown experts said heavy congestion levels - even at night - means it wasn't the best tunnel they reviewed

Sandy Brown experts stated that heavy congestion, even nighttime, meant it was not the most efficient tunnel.

This is a 1.1-mile tunnel under Limehouse in East London on the A1203 road and links to Canary Wharf in London Docklands. 

Built between 1989 and 1993 at a cost of £293,000,000, it has been calculated as the most expensive road scheme in Britain per mile – around £50,500 per foot at 2011 prices.

With a long ascent that requires the engine to work slightly harder, and a one-way traffic system, Limehouse tunnel ranked lower down the list due in part to the volume of traffic driving through it, which is typically high at all times – even late at night. 

Side tunnel merging can lead to more congestion as drivers switch lanes.

=7. Hatfield Tunnel, Hertfordshire (A1M)

Length: 1,200 metres

Speed limits 70mph

 Obsolete measurement 8th

While the shape of the Hatfield tunnel isn't best in terms of acoustics, the 70mph speed limit does give it an advantage over other tunnels already mentioned in this list

The Hatfield tunnel has a poor shape in terms of acoustics. However, it is faster than other tunnels in the list at 70 mph.

The Hatfield Tunnel was constructed in 1980 to alleviate congestion and improve retail space. The Galleria’s designer outlet can also be found at the top of the tunnel.

Hatfield, another tunnel that has a great one-way traffic system which helps it score. Hatfield’s motorway speed limit is different from other tunnels of lower speeds (30 mph) seen here.  

This was due to noises from the road, which can be heard above any engine and exhaust sounds. Alfa’s study found that Hatfield Tunnel is currently under road resurfacing. It might be higher once it is complete.

=7. Dartford Crossing Tunnels, Kent (A282)

Length: 1,430 metres

Speed limits 50mph

 Obsolete measurement 5th

The West Dartford tunnel (pictured) was first used be cars in 1963 and the East tunnel in 1980

Pictured: The West Dartford tunnel was used first by cars in 1963, and the East tunnel in 80

High wind noise and noisy tar joints on the road surface spoiled what could have been a high score for the Dartford Crossing tunnels

The tunnels at Dartford Crossing were not able to score a good score due to high wind noise and noisy asphalt joints.

Dartford Crossing is one of the most used tunnels on this list. It hosts approximately 160,000 vehicles per day who use the tunnels to cross the Thames. 

In 1963, cars used the Western tunnel first. The Eastern tunnel was opened in 1980. Both became northbound when the bridge in 1991 was built to allow southbound traffic. The toll for cars to cross is £2.50.

Acoustic experts said the upward slope in the Dartford tunnel produced a good sound as the engine needs to be engaged to maintain speed, and a one-way traffic system ensures there’s little disturbance from oncoming cars. 

The tunnel’s high wind noise and the crackling road surfaces on its surface made it difficult to hear, so the marks were missed. 

=5. Queensway Tunnel, Merseyside

Length: 2,010 metres

Speed limits 30mph

 Obsolete measurement 9th

One of the longest and oldest tunnels in our list is Liverpool's Queensway tunnel. Experts said the profiling of the tunnel walls ruined the sound quality of the engine and exhaust of the car

Liverpool’s Queensway tunnel is one of our longest and most ancient tunnels. Experts believe that the walls of the tunnel were profiled to ruin the car’s exhaust sound and engine performance.

Liverpool’s Queensway tunnel runs underneath the River Mersey, linking Liverpool to Birkenhead. 

Opened in 1934, it’s one of the oldest tunnels in our list and drivers of cars have to pay £1.80 each time to use it.

Although the tunnel was long and had a great road surface, there was a noticeable ‘ticking effect due to profiling. This affected the sound measurements made by testers. 

Additionally, the noise created by narrow streets and uneven road markings was distracting from the car’s grumble. 

=5. Holmesdale Tunnel, Enfield (M25)

Length: 600 metres

Speed limits 70mph

 Obsolete measurement 4th

While the M25 will certainly not be a favourite for petrol heads, the Holmesdale tunnel will be part of the usually-gridlocked motorway they can enjoy

The M25 is not going to be the favourite of petrolheads, but the Holmesdale Tunnel will be an option for them on the normally-gridlocked motorway.

While the rectangular tunnel wouldn't normally be best in terms of generating engine and exhaust sounds, the acoustic study found the good road surface resulted in a clearer note from the car

The rectangular tunnel isn’t the most efficient in terms of exhaust and engine sounds but the study revealed that the good road surface produced clearer notes.

This tunnel is one that makes up the dreaded M25 between the Hertfordshire town of Waltham Cross and the northern fringe of Enfield. 

Alfa Romeo found the Holmesdale tunnel to be an exception with its placement in the top 5.

Although its tunnel is rectangular and contains four lanes for fast-moving traffic, the exhaust echo may not be optimal. However, the good roads and the traffic splitting into different sections improves the sound quality.

4. Hindhead Tunnel, Surrey (A3)

Length: 1,830 metres

Speed limits 70mph

 Obsolete measurement 7th

The Hindhead Tunnel's cylindrical bore resulted in a booming V6 engine note from the Alfa Romeo Stelvio Quadrifoglio (pictured)

A booming V6 engine note was heard from the Alfa Romeo Stelvio Quadrifoglio through the Hindhead Tunnel’s cylindrical bore (pictured).

Hindhead Tunnel was opened as part of the 4-mile Hindhead bypass. It replaced the A3’s last single-carriageway section linking London and Portsmouth. 

The tunnel runs under the Devil’s Punch Bowl and is considered the longest road tunnel that’s not forestuarial.

The cylindrical bore tunnel, which measures 1,830m in length, was deemed by experts at Alfa Romeo to have a great road surface.

This resulted in it performing well in subjective test, and the engineers said that the SUV’s V6-powered engine was pleasant to hear from the interior. 

3. Beaminster Tunnel/Horn Hill Tunnel, Dorset (A3066)

Length: 105 metres

Speed limits60 mph, though caution to slow down

 Obsolete measurement 3rd

The shortest tunnel on the list, which is hidden away in the Dorset contryside, is deemed one of the best in terms of engine and exhaust acoustics

Hidden away in Dorset, the shortest tunnel is one of the most excellent in terms of exhaust and engine acoustics

Many of these tunnels are located on dual carriageways or fast motorways. However, this tunnel is in beautiful Dorset countryside.

The Beaminster tunnel – also known as Horn Hill tunnel – is the shortest in the list at a mere 105 metres and, having been constructed between 1830 and 1832′ is one of the first road tunnels built in Britain.

Drivers approaching the bridge are restricted in space. They may be able to travel up to speed limit, but they should slow down due to its narrow construction. 

On a clear run this U-shaped configuration works in drivers’ favor. Experts Sandy Brown say that it allows them to hear the engine very clearly. 

2. Saltash Tunnel in Cornwall, (A38).

Length: 410 metres

Speed limits 30mph

 Obsolete measurement 1st

Saltash tunnel is proof that high road speeds are not essential for making the best noise

Saltash Tunnel is proof that it’s not necessary to have high road speeds in order to make the most noise

Saltash Tunnel, which was inaugurated in 1988, has unusually three lanes. For holiday or rush hour traffic, the central lanes can be used as a reverse lane. The lane is used by 38,000 drivers per day at an average length of 410 metres.

This tunnel shows that you don’t need to be able to go fast in order enjoy the tunnel from your car. 

Although drivers may be limited to 30 mph, there was no wind noise or high tyre pressure that could drown the engine. The V6 Bi-Turbo is clearly audible and can only be accessed with a soft throttle.

1. Penmaenbach Tunnels in North Wales, (A55)

Length: 658 metres

Speed limits 30mph

 Obsolete measurement 2nd

And the winner is... Penmaenbach tunnels in North Wales. Its distinctive U-shaped profile, good road surface and one way traffic configuration makes it the best tunnel for petrol heads

And the winner is… Penmaenbach tunnels in North Wales. This tunnel is the perfect choice for petrol heads because of its distinctive U-shaped profile, excellent road surface and one-way traffic configuration.

Alfa Romeo ranked the Penmaenbach Tunnels in North Wales as the most enjoyable for petrolheads to listen to the motors.

These tunnels make up the A55 trunk road, which runs between Conwy, Penmaenmawr.

Penmaencbach ranked highest in vehicle noise analysis and subjective reviews by Sandy Brown. It has a unique U-shaped profile with a great road surface, one-way traffic configurations in all tunnels, and a distinct U-shaped profile. 


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