The Economist: “Around one heart attack in 50 in rich European countries is caused by chronic exposure to loud traffic, according to the World Health Organisation (WHO). The ill-effects of noise pollution in such countries are second only to those from dirty air, says the WHO. Long-term exposure can cause hormonal imbalances as well as mental-health problems. Roadside barriers can help dampen the racket, but they are expensive—up to $600,000 per kilometre—and they often serve as magnets for graffiti. Besides, they work less well on windy days and are impractical along city streets. Happily, there is another option. By adding rubber “crumbs”, reclaimed from shredded tyres, to the bitumen and crushed stone used to make asphalt, engineers are designing quieter streets. First used experimentally in the 1960s, this rubberised, softer asphalt cuts traffic noise by around 25%. Even better, it also lasts longer than the normal sort.”