Why you are always driving uphill

[FRiSson]

http://web.mit.edu/newsoffice/2012/p...ires-0523.html

The researchers found that the weight of your vehicle on asphalt surfaces causes the pavement to deflect slightly downwards. As a result, you drive in a continual trough and the wheels are always going uphill.

[Snoopyalien24]

Perfect! Now we can invent hover cars!

[Dadhawk]

Originally Posted by FRiSson

http://web.mit.edu/newsoffice/2012/p...ires-0523.html

The researchers found that the weight of your vehicle on asphalt surfaces causes the pavement to deflect slightly downwards. As a result, you drive in a continual trough and the wheels are always going uphill.

Nothing new here. I learned this the first season of "Ice Road Truckers".

[FRiSson]

Actually very little research has been done on deflection in asphalt. Deflection on surfaces such as ice is not exactly equivalent, since the substrate is sometimes unfrozen water or soft materials such as gravel. Track deflection has been observed in railroads for 190 years. However, because freight railroads lack suspension systems, the deflective surface acts as a kind of shock absorber to save the train from being rattled to pieces.

The implications of this current line of research is that we have built our highways using asphalt because it is cheap, but using harder materials would save us around 3% a year in fuel use. That may offset the higher costs of using harder pavement materials such as concrete instead of asphalt.

[mattles]

I dont know about you guys, but I tend to like asphalt. Since its much softer than concrete and other typical road materials, it usually results in a less jarring ride (if maintained properly.) The rubberized asphalt that phoenix is currently using on all of the ring roads/freeways/etc is just delightful to drive on because it is so soft.

[motofan]

that may help, but here people don't maintain road...

[86X86]

I actually kinda miss the "thump-thump" going over the expansion joints of a concrete freeway-- gawd I gotta get out of Alaska...

[SkullWorks]

this is the problem with PHD's, they literally can't think, they are too busy "understanding"

without tires that deflect less than the road, no real effect will be made.


where does all of this energy go that is used to deflect the road, does it not equally react at the backside of the tire?and effectively propel you? Does asphalt actually have time to compress while covering 1 mile per minute or approximately covering the tires effective contact patch width 264 times per second?

(5280/60=88' per second or 1056" per second/~4" long contact patch=264)

how bout we focus on the real traffic issues that could gain/cost 10-20% like stop light sequencing. staggering work hours for industries to limit max usage of highways, fix ACTUAL road problems like uneven roads, pot holes, poor civil engineering ETC.....

GRRRRR


/rant

[peter]

Originally Posted by FRiSson

Actually very little research has been done on deflection in asphalt. Deflection on surfaces such as ice is not exactly equivalent, since the substrate is sometimes unfrozen water or soft materials such as gravel. Track deflection has been observed in railroads for 190 years. However, because freight railroads lack suspension systems, the deflective surface acts as a kind of shock absorber to save the train from being rattled to pieces.

The implications of this current line of research is that we have built our highways using asphalt because it is cheap, but using harder materials would save us around 3% a year in fuel use. That may offset the higher costs of using harder pavement materials such as concrete instead of asphalt.

Yes I agree with you post, really expose the idea very well.

[Infernal]

needing to slow down for speed bumps, traffic lights and traffic in general probably causes mor pollution, fix these, then we'll talk about harder pavements!