The rolling noise made by motor vehicles has been a major source of discomfort to people for centuries. Significant reductions in noise emissions from motor vehicles have been achieved in the past decades through measures affecting the material, construction, contour and above all, the tread pattern of the tire. Nowadays, six modern cars generate as much noise as one single car manufactured in 1980, and thirteen modern commercial vehicles are no louder than one single commercial vehicle from 1980.

Urban traffic noise can almost be divided equally between propulsion noise and tire/road noise. Traffic noise comes from a variety of sources. The engine, the powertrain, the rolling noise of the tires on the road and the noise of the wind in the vehicle body all contribute to the actual traffic noise. Depending on vehicle speed, sometimes the one, sometimes the other factor plays a bigger role. In cities and residential areas in particular, traffic noise is dominated by start-up operations, which, in turn, are determined at low speeds by the powertrain system, and at speeds in excess of 50 km/h by tire/road noises.

Achieving effective reductions in road traffic noise levels requires above all a concerted approach. Further advances in reducing traffic noise in cities and residential areas are possible only if vehicle manufacturers, road builders and city planners put their heads together. What can be realized by way of noise reduction on the tire alone has more or less been exhausted according to the current state of the art. Intensive groundwork is required to achieve further reductions in traffic-related noise. Even with today’s technical mastery, a significant reduction in tire/road noise would not be possible without impairing, at least partially, certain safety-related performance characteristics of the tire.

The market demands that modern tires provide a balanced spectrum of properties. Here, the conflict between design objectives like driving safety, a long service life and environmental issues must be solved. Ongoing improvement requires intensive research and development work. Continental has therefore been investing heavily in modern testing and simulation methods at its own test site, the Contidrom, and at its acoustics center for decades.

Continental is involved in joint research projects with the German Federal Highway Research Institute, manufacturers of road-building equipment and construction machinery, universities and automobile manufacturers with the aim of arriving at a deeper understanding for the mechanisms in the contact zone between tire and road. The partners have set three major targets: development of a simulation tool that makes it possible to minimize tire/road noise already on the computer; development of noise-reduced tires, and development of quiet road surfaces.

The Corporation is involved in national and European initiatives for reducing tire and road noise, including the European Union’s SILENCE research project, as well as the “Quiet Traffic” and “Quiet Road Traffic” projects across Germany.