Technical assessment of the effect of regulations on road vehicle noise

How to transform vehicle-type approval tests into an effective global noise policy instrument

“…Several investigations during the nineties have shown undoubtedly that the decrease in noise emission from passenger cars on motorways and urban expressways ranges from 0 to 1 dB(A), while the decrease of noise emission of trucks ranges from 2 to 4.5 dB(A). [2][3][4] Both figures are much smaller than the reductions that have been achieved in the tests. The explanations for these astonishing facts are discussed below.…”

A New Vehicle Noise Measuring Method Replacing the Iso 362 Principle

“…This method is receiving increasingly serious criticism for regulating noise emission inef ciently. In an extensive evaluation of the effect of emission limits, made by a working party under l-INCE [1], it was concluded that only minor parts of the nominal tightenings of noise limits were effective as environmental improvements. Therefore, it was recommended that "A new measuring procedure for use during type approval of vehicles shall be developed.…”

“…trucks are loaded). Since noise reductions measured in actual traf c appear to be more signi cant in Japan than in Europe, it may be that the use of a more realistic driving condition during type approval is one of the main reasons [1].…”

Noise Control of in-Use Vehicles - New Norwegian Legislation

“…This has been thoroughly discussed by an international working party established by l-INCE in 1992. Their nal report [1] identilied the main reasons. Among them: lack of realism and representativin at driving conditions in the type approval lest.…”