Maximising motorway noise reduction with minimal visual impact
There are several methods of noise reduction for motorway traffic, ranging from acoustic insulation in vehicle engine bays and underbodies, to tree belts and large acoustic fences positioned alongside the carriageway.
For those living within a visible range of the motorway, these various different methods can have different aesthetic impacts – and of course acoustic insulation in vehicles themselves, combined with tyres that produce lower noise levels in contact with the road, are among the techniques with minimal visual impact.
In a University of Sheffield PhD thesis, Like Jiang looks at the integrated impact of motorways, combining both their visual and aural effects on nearby residents into a single overall measure.
He writes: “The results showed significant visual impact from motorway traffic which was higher in the natural landscape than in the residential counterpart, increased by traffic volume and decreased by distance.”
The findings indicate that in more urban areas, residents may be less distracted by noise barriers along the side of the motorway, whereas high barriers are less welcome in the countryside.
Acoustic insulation in vehicles themselves offers one way to minimise the noise of traffic, without needing visible barriers by the roadside.
By eliminating unwanted noise at its source, this also helps to reduce it emanating outwards in all directions – overcoming the need for external acoustic barriers to be excessively long or tall to block out more of the sound.