quantified for big trucks by cummins a few years back
Relative Rolling Road Surface Resistance %
Concrete polished (best mpg) –12%
new baseline
Asphalt with finish coat 1%
medium coarse finish 4%
coarse aggregate 8%
Chip and Seal Blacktop (worst mpg) 33%
Road roughness can increase rolling resistance up to 20% due to energy dissipation in the tires and suspension (10% loss of mpg).
taken from p. 26 at
http://cumminsengines.com/assets/pdf...whitepaper.pdf