Road Traffic Noise & Soundproofing
When it comes to soundproofing for road traffic noise there a few key factors we need to consider before deciding on a solution.
- The type of traffic (trucks, cars, motorbikes)
- The road type (A roads, residential with speed bumps, etc.)
- The distance from the origination of the sound
The Noise From Vehicles
To understand the noise emission levels from vehicles there are 3 key factors: speed, acceleration and a constant for the vehicle which includes the size of the car and its dominant frequency range.
Road Traffic Noise Examples
Regardless of where you live, ‘light vehicles’ – your average car – will account for most of the traffic noise. Even in areas where the percentage of heavy vehicles is greater than average, cars will dominate as they tend to travel at faster speeds.
Cars produce two types of noise: propulsion noise and tyre noise. Under 34 mph, propulsion noise will be the dominant issue, over that level the sound of tyres on the road is the main cause. However, due to advancing engine technologies, tyre noise from new vehicles can rule over just 12 mph.
- The legal noise limit for a car exhaust in the UK is 82dB.
- The average car produces 62dB driving at 30 mph.
- At 50 mph, a car produces noise emissions of ~70dB.
Car Noise Pollution Reduction
It has been found that in residential areas in which the speed limit is between 30-60 km/h, reducing the limit by 10 km/h can cut noise levels by 40%. On urban motorways a reduction from 70 mph to 60 mph cuts noise pollution from light vehicles by up to 50%. However, the same reduction in speed does not equate to the same reduction in road traffic noise pollution for heavy vehicles.
Acceleration can account for 10% of traffic noise, and so the installation of speed bumps theoretically reduces noise pollution. In reality, most drivers will accelerate and decelerate between bumps, as well as creating impact noise when they reach the bump.
When it comes to road traffic noise pollution trucks are disproportionately responsible due not only to their size, but the height of their diesel stack. This can be a particular problem on smaller backstreets where the truck is likely to accelerate and decelerate, and where body rattle is more audible. In areas where trucks frequently make deliveries, the reversing siren presents another pain point that needs to be factored into the solution.
- Drop-sided trucks produce noise in the range 40-50 Hz mostly due to exhaust noise.
- HGVs have two frequency peaks: 63 Hz and 630 Hz, due to exhaust and body rattle.
Whether it’s your neighbour revving their engine first thing in the morning, or passing traffic, the noise from motorbikes can be especially intrusive. And while there are restrictions on the noise level of motorbikes, these vary depending on when the bike was first used, meaning that you can often hear bikes producing noise of over 80 dB, mostly in the tricky to combat low and mid-low range.
- Cruiser bikes (Harley Davidson type typical), produce noise that tends to lie predominantly in the 100-400 Hz range. 84.8 dB Lmax
- Mopeds and scooters tend to dominate the 1000-2000 Hz range, with a broad range from 200-5000 Hz. 62.3 dB Lmax
- Sport bikes tend to have a fairly flat spectrum in the 125-8000 Hz range. 78.3 dB Lmax
Road Traffic Noise Solutions
As you can see above, to soundproof against road traffic noise is a tricky business and requires a good understanding of noise complaint itself. To be most effective, we offer noise surveys that measure the decibel level of traffic noise as well as the frequency. This helps us to create a solution that will work against the range of the noise you encounter, as well as the maximum decibel level of the traffic.
Our Wall Soundproofing Systems
The window is the weakest link in any property. And unless adequately soundproofed and professionally installed, they will let in a lot of noise.
We install specialised windows fitted with glazing of two different thicknesses to combat the resonance frequency of your specific noise complaint.
Walls are generally good insulators of sound, but they are prone to problems too. The most common issue when it comes to road traffic noise is gaps in the structure itself.
We locate and plug these gaps with acoustic materials and install soundproof ventilation where necessary.
Whether it’s around the frame, or through the door itself, noise will find a way to get in.
In many cases the professional installation of soundproof doors will drastically cut the noise emissions entering your property.
How to Minimise Road Traffic Noise Yourself
If you’re looking to reduce road traffic noise but can’t make changes to your property, there are a few solutions you can try yourself. Do bear in mind that these solutions will not have the same effect as installing new windows and doors.
- Use insulating tape around your windows and doors to prevent noise entering through any cracks.
- Noise blocking curtains provide another barrier against noise inside the home.
- Trees can be planted around the perimeter of the home, which will reflect the noise back onto the street.
- Erecting a solid fence will also reflect the noise back onto the street.