Making Quieter Highways

An anonymous reader writes "Researchers at Purdue are investigating ways to make life for those who live near major highways more quiet. They have found that most of the noise is literally where the rubber hits the road, not engine noise or even passing winds. The team has come up with a new form of pavement that is in testing in Arizona and will soon be installed in California. The pavement is simply asphalt with some mixed in rubber."

liars and thieves

[passthecrackpipe]

A similar compound was invented in the Netherlands ages ago, using concrete (cheaper and easier to handle then rubber). It is called ZOAB ("Zeer Open Asfalt Beton", meaning "Very Open Asphalt Concrete") This highly porous material has several beneficial properties, such as being more quiet, and more efficient in draining water, thus preventing aquaplaning. It is a safer road, alltogether. Now some university is passing this off as a "Great American Invention"?!?!

Same thing happend with airport groundradar. A Norwegian Company invented a groundradar system for airports, allowing safer manouvering of aircraft in dense fog and other low viz situations. This delivered tremendous safety to airports. The FAA wanted it, but it had to be american - can't buy of those eurotrash companies and all that. 8 years down the line, and it still was not working. In the meantime, you have had about 33 near misses at o'hare alone.......

Obviously I shall now be modded down -50 "unpatriotic eurotrash bastard" whatever.

Re:Side effects.

[Cy Guy]

Yeah, the article sites the cost of repaving at "$325,000 per lane mile." whic makes me wonder a couple of things, how long will that last until repaving, what is the per year cost of maintenance (pot-hole repair, re-striping, etc.), and WHY THE HELL DOES THE CONGRESS THINK AMTRAK SHOULDN'T BE SUBSIDIZED?

Sorry about yelling, but seriously, If AMTRAK needs a $3B/year subsidy that is 1500 miles of 6 lane highway - or about the cost to repave I-95 North to south.

duh

[greentree]

of course it's the rubber hitting the road. here in michigan the road commission made a serious mistake in implementing a "new" type of cement that was supposed to last longer. however, it turned out it didn't last long(er), in fact it did the opposite. and worst of all it had rivets perpendicular to the tires moving over it creating an obnoxious howling noise. i've seen more the one local news coverages on pissed off people living nearby highways that have to put up with terrible noise pollution.

Coefficient of friction

[n1ywb]

From http://www.hronline.com/forums/ohs/0109/msg00073.h tml

The coefficient of kinetic friction of rubber on rubber is listed in this

source as Natural rubber, vulcanised at 100m/min on rubber flooring or
rubber tread vulcanisate, clean, - 1.16. That's pretty high!

That IS pretty DAMN high! The coefficient of friction of rubber on dry asphalt is around 0.6 or 0.7, which is already considered to be pretty high. So logically, adding rubber to asphalt would probably improve the coefficient of friction between the tires and the road, hence decreasing stopping distance and improving cornering.

Physics is the study of everything.

Re:liars and thieves

[passthecrackpipe]

hehehe, very cool. but in fact, since it is government funded study that invented this in the first place, it is in fact open source. A tar is not available *grin*, but a PDF is. [vbwasfalt.org]. It is in dutch though.....

I just saw this on TV

[KurdtX]

I don't quite remember the night, but I saw it on tv recently, and it kind of got me thinking.

Now I've got a sports car with some noise dampering, but generally I can hear everything. The nice thing is it's shaped really smoothly, so I hardly get any wind noise, so just about all the noise coming in from outside my car is from the road. The thing I notice is that even with current roads (I live in San Diego), the biggest difference is on the ones that are concrete - since they don't buckle like asphalt-covered ones do. Sure, I've noticed that some of them have grooves, which is where I suppose the air is going (and to help with skidding in the rare event of rain) - those ones seem to be the most quiet. But even those get loud if they're not graded right.

Hey, think about it, most of the time a car is fairly quiet, but when you go over a bump, your car is usually louder after you land and reach the minimum point. The other thing I'd say is that maybe it's due to the weight of the vehicles, as there's a huge difference between cars and SUVs/Trucks - and motorcycles are silent except for their engines. So maybe the solution is to stop selling SUVs... yeah, I'll keep dreaming.

Re:Tires _in_ the roads

[pmz]

last I heard they had some major problems with galvanic reactions from the ground-up radial belts.

I would imagine that it wouldn't be terribly difficult to build a process that removes ferrous materials from rubber. Melting all the rubber and sticking a big magnet into the goo is one thing that comes to mind. I believe one other metal used in tires is brass, but that shouldn't be as prone to corrosion.

in canada...

[xilmaril]

I guess it's different in the states, and possibly elsewhere, but in canada (or at least the handful of cities I've lived in), they've been using rubber in pavement on busy streets for years.

Re:Coefficient of friction

[Militant Libertarian]

I live in phoenix, they've done this to a part of the I-17 (near 19th ave).. The road is so nice to drive on, so quiet and the handling on it is prime for going 100 at 3AM (though there's probably 6 or 7 fatal crashes at any given moment, just because the drivers here are totally retarded).

they're doing the SR-51 next, but they're taking their sweet time doing it, at this rate I'll have graduated from ASU before they finish it and make my commute more bareable.

Re:I just saw this on TV

[Kiaser Zohsay]

... so I put on loud ass pipes so that even the most insulated SUV can tell I'm coming.

No, they can't hear you coming, but they can hear you leave. Loud pipes are only loud beside and behind you, not in front. "Saftey" is a lame excuse for some macho show-off BS.

Re:Rubberized Asphalt

[Radical Rad]

A valid point. The article I read was many years ago and if I recall correctly it was something like: the rubberized asphalt would cost twice as much but last 5 times as long. This article lamented that there are laws which force the contractors to take the lowest bid which meets the minimum spec so it was not possible to even experiment with the new materials here in the US. Howver it mentioned that the materials were being tried in several places in Europe with good results.

Re:Tires _in_ the roads

[Radical Rad]

Melting all the rubber and sticking a big magnet into the goo is one thing that comes to mind.

Vulcanization of the rubber cross-links the polymers which means that it will not melt anymore. If you raise the temperature enough it will only burn.

I drive on rubberized asphalt every day, its great

[Colonel Blimp]

I drive on a mile stretch of it that was put down in a test on my way to work here in Phoenix, and there is a 12 mile stretch on another highway here. Its quiet, safe, and no problems with braking or anything else. Its quite a pleasure to drive on

Re:Coefficient of friction

[satyap]

That would be because friction is a per-area measure. What you're thinking of is something like friction times area, which is what really matters, of course. Brake pads with a 10x10 cm surface area do better stopping than pads with a 1x1 cm area.