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The research project focused on the changes in noise emissions of the Swiss vehicle fleet and their tires on Swiss roads. The noise emissions at speeds of 50, 80 and 120 km/h were examined in more detail. It showed a decrease of noise emissions of passenger cars in the inner city area by about -2 dB and an increase of emissions in the high speed range by +1.5 dB in the period from 1998 to 2017. The noise emissions of the vehicle category trucks in the inner city area increased in the same period by +0.5 dB and in the high speed range by +3 dB.
It can also be seen that the developments of the vehicles have different effects on the change of noise emissions depending on the respective dominant sound generation type (rolling noise and propulsion noise). Accordingly, future noise emission trends for the individual vehicle categories and speed ranges should also be considered and taken into account separately in each case.