The European Parliament’s Committee on the Internal Market and Consumer Protection has voted to support proposed amended legislation that would make tires quieter and more energy efficient. The legislation, originally proposed by the European Commission in May, will set harmonized minimum noise and rolling resistance standards for tires. Tires not meeting the requirements will note be able to be sold; tires belonging to stocks prior to the dates of new requirements and falling short of the new requirements would still be permitted to be sold.
The new regulation replaces a number of directives, is directly applicable in the Member States and reflects car safety standards harmonized by the United Nations.
The regulation would also require light-duty vehicles (category M1) to be equipped with an accurate Tire Pressure Monitoring System, capable of regularly warning the driver of any loss of pressure in all tires individually in the interests of optimum fuel consumption efficiency and road safety.
Once adopted by Parliament and Council, it should apply from 1 November 2011, say MEPs, a year earlier than the Commission proposed. But various transition periods are provided for, in some cases until 2018, to enable the car industry to adapt to the new measures.
We are going to improved road safety in Europe by going further than the Commission. The new technologies must be pushed ahead faster, to set lower sound limits in future years and thus improve public health by reducing harmful road traffic noise. My main concern is to ensure that this European regulation does not impose extra costs on consumers and manufacturers. We want to see to it that drivers will save money by using less petrol in a healthier environment with lower CO2 emissions.—Andreas Schwab (EPP-ED, DE), rapporteur
A report by CE Delft in 2007 concluded that each year more than 245,000 people in the EU25 are affected by cardiovascular diseases that can be traced to traffic noise. About 20% of these people (almost 50,000) suffer a lethal heart attack, thereby dying prematurely.
While tire noise is one of multiple contributors to overall traffic noise, quieter tires are a cost-effective means of achieving noise reduction, according to the CE Delft report.
Tire noise is generated partly by impacts and shocks on the tire caused by road surface irregularities or irregularities on the tire tread. These shocks make the tire vibrate and radiate noise. Tread vibrations then spread to the sidewalls, amplifying the noise further. Others sources of tire noise include:
Aerodynamic sources such as air pumping, consisting of the noisy pushing away of air on the leading edge of the contact zone between tire and road surface and the noisy sucking in of air along the rear edge. The resonances occurring in the tire cavity and tread pattern canals can also be considered as aerodynamic noise sources.
The stick/slip tread elements’ motion relative to the road surface, causing the tread elements to vibrate tangentially.
An adhesion effect—a stick/snap effect of the sudden loosening of the tire tread from the road surface, comparable to the sudden loosening of a suction cup.
A horn effect— a noise amplification mechanism whereby noise generated near the edge of the tire/road surface contact area becomes amplified due to the geometry created by tyre and road surface. This is the same phenomenon intended by the conical part of a trumpet or a megaphone.