Interstate cement more effecient
 

Anybody else notice this? I have always consistently found interstate cement to be more effecient. Nothing to do with drafting I have completely ruled that out.

Read that concrete was better for mileage a few years ago. Sadly most of the roads here have been repaved with asphalt and it seldom last more than a couple of years.
Some of the few concrete sections of Interstate here were built in the late 1960S. They have been repaired numerous times and even ground down smooth on occasion.

regards
Mech

Yep

Rolling Resistance

Part way down has a chart. Car tires on concrete have about half of the Crr as car tires on asphalt.

Depends a lot on the condition of the concrete. New is pretty good; old, cracked, and potholed isn't. And then there was I80 west of Donner Summit a few years ago, where traffic had worn ruts deep enough that I worried about high-centering the Insight on them.

I think fresh, smooth-rolled asphalt is actually the best. (Just seat-of-the-pants opinion from driving the Insight on various surfaces.) Unfortunately it never stays smooth very long :-(

Understatement of the year! The street in front of my house was resurfaced last fall and already it's so full of cracks- both lateral and longitudinal- that it looks like it's 20 years old. :rolleyes:

Our roads down here must be very good there's always new construction on interstate but even the interstate sections not touched in at least 6 years a great!

Your stories remind me of the interstate going from terre haute in to Indianapolis whatever that interstate was, it was HORRIBLE my lifted land rover was scary with how deep the pot holes were.

In completely unrelated news, tires don't grip concrete very well.

...steel rails (railroad) have lowest Crr; steel is very smooth.

...concrete has lower Crr than asphalt; conrete is smoother than asphalt.

...asphalt has higher Crr than concrete; asphalt is rougher than concrete.

On the other hand, asphalt road racing tracks are a total blast, especially with sticky tires. Fuel mileage.....not so good.....

They recently resurfaced the asphalt highway on my commute...they scraped the 1/2 inch top layer off and then put down tar-like substance, covered the tar in rock chips and then vibration rolled it. Grips awesome in the winter but is really bad on tires and fuel economy until it wears down a bit...

...its too bad 1/2 my commute has this covering...or else I would be getting better numbers. :(