Various methods have been proposed to reduce greenhouse gas (GHG) emissions associated with transportation. We investigate the potential of increasing the elastic modulus of pavement surface layers across the entire U.S. pavement network as a means of lowering vehicle excess fuel consumption (EFC) resulting from deflection-induced pavement–vehicle interaction. We show that in a business-as-usual case deflection-induced EFC represents up to 2660 million metric tons (Mt) over a 50-year analysis period. Elastic modulus increases can be accomplished using several currently implementable methods. The analysis shows that increasing the modulus of elasticity using 10% resurfacing in the network per year leads to an 18% reduction of GHG emissions from the pavement network, or 440 Mt CO 2 eq, over a 50-year analysis period. This would potentially offset 0.5% of the future GHG emission of the whole transportation sector.
grewestr on June 27th, 2020 at 12:24 UTC »
As an engineer who works in vehicle dynamics and tire-road interactions on a regular basis, I have an extremely hard time believing that this is accurate at face value. If there were an achievable 18% difference in fuel economy due to the road drag, we would have noticed it by now.
We run thousands of tests in hundreds of vehicles that characterize the road drag directly and I have not observed this effect at all. In our data, there is no discernable difference between concrete and asphalt if both are smooth surfaces. There may be a couple percent if we look very closely, but nowhere near enough to make almost a 20% fuel savings. Concrete is generally used because it is more durable, not for fuel economy.
The details in the abstract are too few for me to discern if the authors are misstating the premise, or if their experiments are not reflective of reality. It seems to me that if they are comparing a road made out of silly putty to concrete, then they would get these savings. However, this is not plausible for the real world because we have mostly asphalt or dirt roads, not elastic ones.
redneckrockuhtree on June 27th, 2020 at 12:23 UTC »
Wouldn't stiffening the roads also make them more vulnerable to damage from frost heave and water freeze/thaw cycles?
KaizDaddy5 on June 27th, 2020 at 12:08 UTC »
What does it mean by "stiffening".
Suring it up? Or like straightening (either curves or hills)