Traffic noise is an obvious issue for many people, particularly in high-density areas. Much of that noise comes not from engines, but from the vibrations caused by tires on the road. This can be demonstrated by the fact that, while a hybrid is notoriously silent in all-electric modes at slow speed, as soon as it speeds up (even when it remains in electric mode), the sound is not that different to any other modern, relatively efficient motor vehicle, at least to this author's ears. Now researchers in Japan have come up with a new technology to significantly reduce traffic noise, possibly by as much as 90%, by using 'elastic' pavement made, appropriately enough, from old car tires. The researchers claim many other advantages also:
"This pavement has many additional features. One of these is resistance to ice formation, as the high elasticity allows the weight of the car to break the ice into pieces. In addition, as the high proportion of voids contributes to better drainage, slip-resistance and water-splash prevention can also be expected."
Unfortunately, we can't find details of the effect that this surface may have on fuel consumption. Would the high elasticity lead to better traction, and therefore improved fuel economy, or increased drag, therefore reducing efficiency? Any automotive engineers or physics majors, feel free to enlighten us in the comments section. We'd also be interested to know if this would add to the calls for hybrids or electric cars to incorporate 'artificial' noise for road safety reasons — getting clipped by a silent car in the parking lot is likely to hurt an awful lot less than if it is doing 30 mph through the center of town. Of course, ultimately, reducing traffic volume through better planning and encouraging alternatives should be our goal, but many urban dwellers would be grateful for any noise reductions in the meantime! ::LOHAS::