TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 526: Inertial Profiler Certification for Evaluation of International Roughness Index determines the state of practice of certification of inertial profilers at the national and international levels. Inertial profilers are used to collect the repeatable and reproducible road profiles analyzed to calculate a smoothness or ride quality index, the most common of which—the International Roughness Index (IRI)—is a performance measure that state departments of transportation (DOTs) must report to the Federal Highway Administration (FHWA) as part of Highway Performance Monitoring System/Moving Ahead for Progress in the 21st Century (HPMS/MAP-21) Act and Fixing America’s Surface Transportation (FAST) Act requirements. The information in this report can help ensure that accurate data are collected both for smoothness specifications at the project level and for MAP-21 Act and FAST Act requirements that the states provide accurate and consistent IRI data.
The report is accompanied by the following appendices:
