View Single Post
Old 03-28-2012, 11:24 AM   #8 (permalink)
gone-ot
...beats walking...
 
Join Date: Jul 2009
Location: .
Posts: 6,190
Thanks: 179
Thanked 1,525 Times in 1,126 Posts
...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.
  Reply With Quote