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During the latest decades tirelroad noise has been recognized as one of the most significant parts of road traffic noise. It has therefore become necessary to employ suitable noise reduction measures on tires as well as road surfaces which do not impose safety problems. Since many of these measures rely on appropriate measuring methods, several activities in order to standardize such methods for tirelroad noise have started. The paper begins with a systematic analysis of the rather complicated tirelroad noise problem and suggests ways to solve it. Then a review is presented of the major measuring methods considered for standardization with regard to classification of tires: The coast-by method The trailer method The laboratory drum method The trailer coast-by method The advantages and disadvantages as well as which applications are the most suitable for each one are discussed. Particular attention is paid to the extremely important question of test track surface selection.

This paper summarizes a presentation that attempts to describe what has recently been done and is planned to be done to relieve the problem of traffic noise, with focus on tire/road noise emission. The paper shows that there is at the moment in Europe, Japan and in countries accepting ECE Regulations a quite intensive development aiming at reduction of road traffic noise, but with initial high ambition often ruined when it comes to the political process. The author thinks that it is likely that many Asian countries under fast development will adopt similar policies as Europe and Japan, although actual implementation may be slower than formal policies would suggest. This positive development applies to exterior noise from light vehicle power units, from car tires and from pavement properties. The exception is trucks and buses and their tires, which are left without significant improvement in the foreseeable future and thus may have an effect on the future perception of truck traffic.

An indoor road-wheel facility at the Technical University of Gdańsk was used to study the noise emission from a variety of tires with different tread patterns. The tires were run both on a smooth steel drum and a drum covered by a replica road surface. All tread patterns were hand-cut to generate several families of simple treads with regular pitch for a systematic study of how groove design influences noise. Most of the observed, tread influenced phenomena could be explained by generation mechanisms such as radial vibrations induced by tread block impact, pocket air pumping and pipe resonances in the grooves. For instance, it was observed that, when speed increases, sooner or later the tread block impact frequency will coincide with the pipe resonance frequency and then generate excessive noise at that speed.

For more than a century, pneumatic (air-inflated) tires have totally dominated the market for road vehicle tires. However, in the recent two decades, interest has grown in developing airless tires. Some of the authors were involved in design of an early version in composite material 15-30 years ago for passenger cars. Presently, the EU project LEON-T (Low particle Emissions and lOw Noise Tyres) includes a part in which prototypes for innovative heavy goods vehicle (HGV) tires are developed, with the main purpose to reduce noise emission by 6 dB. To reduce noise that much it is believed that airless tires are needed. A special challenge is to get a durable design able to carry typical truck tire loads. This paper introduces the principal design of airless tires. Airless tire prototypes are intended to be developed by partner Euroturbine, in cooperation with mainly Applus+ IDIADA, VTI and subcontractor Lightness by Design.