Motorcycles account for some 10% of all motor vehicles in traffic. Their annual mileage is considerably lower than that of the other types of motor vehicles. Nevertheless, they are perceived as the most bothersome source of road traffic noise, even surpassing heavy-duty vehicles. Noise emission is still high for many motorcycles, and the noise problem is aggravated by the fact that they are frequently used by people just for fun - while the peace of others is disturbed. The research into the reduction of noise from motorcycles, which has been performed to date under contract to the Federal Environmental Agency (Umweltbundesamt), has mainly focused on two areas: (a) ascertaining the possibilities for reducing noise levels through technical measures; and (b) anti-tampering measures for motorcycles with limited speeds. Through optimization of the load change silencer as well as additional measures aimed at modifying or encapsulating the engine, it was possible to achieve reductions in noise emissions of up to 7 dB(A) (mofa / moped) and of up to 10 dB(A) (motorcycle) for series-produced vehicles. Since entry into force of the "anti-tampering catalogue" for all motorcycles with limited speeds as of January 1,1986 as well as the use of improved methods of "on-the-spot" checking, the number of vehicles in this category which are still particularly conspicuous in terms of noise is negligible. Technical measures alone cannot be expected to solve the noise problem. In future work, emphasis will therefore also be placed on the investigation of the relevant sociological and psychological aspects of motorcycling.
Abstract