A Federal Highway Administration (FHWA) Technical Review Panel (TRP) met by web conference in June to review models for pavement-related vehicle operating costs and excess fuel consumption. Jim Mack, CEMEX, Past Chairman-ACPA, and ISCP Member, along with Leif Wathne, Executive Vice President-ACPA and ISCP Director, represent the concrete pavement industry on the panel.
This research effort is an outcome of legislative language in the FAST Act asking the Department of Transportation (DOT) to, “analyze impacts of different types of pavement on all motor vehicle types … specifically examine the impact of pavement deformation and deflection.” The study is now in its second year and there has been progress in showing how both roughness and stiffness impact vehicle fuel consumption. However, to what degree is context sensitive?
In general, for heavy vehicles at slow speeds and high temperatures, pavement stiffness can dominate the pavement-vehicle-interaction (PVI)-related excess fuel consumption.
Some work remains to compare the strengths and compatibility of the various peer-reviewed PVI models, but it’s clear that both roughness and stiffness (structural response) are important. Case studies are also being developed to clearly demonstrate the relative importance of each of the PVI impacts (roughness, stiffness, and texture) for a specific set of circumstances/conditions. These case studies will also provide guidance on trade-offs and other pertinent information that will enable highway agencies to make better decisions about strategies to adopt that will reduce pavement-related excess fuel consumption.
This FHWA research effort is expected to wrap up by the end of this calendar year.