Recycling Tires to Reduce Tire Noise
by Sami Grover, Carrboro, NC, USA on 05. 8.07
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::
Sounds like letting the air out of your tires...
Recycled tires going back into the roads are nothing new, its been done for many years with blacktop. They mix the recycled blacktop with the tires and anything else they can use.
I'm no expert, but I would guess it would reduce fuel efficiency. I wouldn't think that increased traction would result in better fuel efficiency unless you were actually "squealing your tires". However, the spongier road would increase drag on the tires.
Again, just gut-instinct physics, but my two cents.
ok I'm an automotive engineer, so here's my $0.02: a lot of new pavement already incorporates rubber particles from used tires. To use a system with a 'tread' designed into it would help with water drainage and prevent ice formation, however it would likely result in a small fuel economy penalty due to the 'squishiness' of the blocks as they deform under weight. Most cars would also tend to feel vague and less responsive in the steering, possibly offsetting any safety advantage.
So the fuel economy issue would easily trump the noise issue in most cases. That being said, the goal of improved fuel economy also brings with it the goal of reducing the weight of a vehicle, which reduced the size of tire needed and the pressure on the road, which reduces the noise.
as a mechanic i find this a load of rubbish. who cares. is this helping our planet one bit. no! its usless research taking up natural resources for wat. some japaness man to say that we may have a 2% decrease in sound from tires by 2050. so wat!!!!!!
I would disagree with some of the previous posters as to the benefits of this. Noise is an environmental concern, and a 90% reduction in road noise would be welcomed by the millions of people living near major thoroughfares.
Although I agree that if there were any effect on fuel efficiency it would be negative, I don't believe it would be significant -- certainly not in comparison to the noise reduction. In California, it's easy to see that using this to re-surface the major 4 and 6 lane urban roads that run adjacent to major residential areas would offer great improvement in noise, but little change in overall fuel efficiency for the stop-and-go traffic. Longer runs between population centers where the fuel efficiency might be more significant wouldn't benefit from the noise properties and wouldn't be good candidates.
Furthermore, this type of technology -- a simple replacement for an existing technology, one that doesn't require re-designing of infrastructure or the adoption by thousands of individuals (imagine how many roads would be changed if Caltrans alone adopted this) is exactly the kind of solutions we need to pursue.
Okay, so it won't reduce greenhouse gasses, but long-term quality of life is exactly what the green movement is about.