A modern road vehicle makes as much as 90% less noise than its equivalent from the 1970s.
Today's motor vehicles are 90% quieter than they were when the issue of vehicle noise began to be legislated on in the 1970s. This striking advance is a testament to the commitment the industry made to producing quieter vehicles. Consumers demand increasing refinement from their cars, trucks and buses, so there is a clear business imperative to offer vehicles that are comfortable to be in or around.
Dealing with vehicle noise is complex, as the sound produced by a vehicle derives from many vehicle components and the objects interaction with the road and air. Calculating and implementing reductions is also a challenge due to the fact that sound levels are presented logarithmically. This means that a 3 dB(A) reduction is actually a 50% cut.
Industry efforts have reduced the noise produced by the average passenger car from 82 dB(A) to less than 74 dB(A) now. New legislation is likely to push this figure down even further, making the total reduction in vehicle noise nearly 99%. Achieving this reduction will require work to be carried out by tyre manufacturers, infrastructure providers and vehicle operators.
Concerns have been raised that making vehicles particularly quiet may have an impact on safety, as pedestrians may not be able to hear a car approaching. Further, the reducing of vehicle noise has ambiguous effects on its environmental performance. In addition to the increasing marginal cost of each unit of sound reduction, the industry stresses the importance of balancing the benefits relative to the investment required for their realisation.