Book Description

Pavement smoothness (or roughness) is used by state highway agencies for monitoring network condition and other purposes such as assessing construction quality and optimizing investments in preservation, rehabilitation, and reconstruction. States are also required to report the International Roughness Index (IRI) as an element of the federal Highway Performance Monitoring System (HPMS). Because IRI is not measured directly but is calculated as the mechanical response of a generic quarter-car, traveling at 50 mph, to the elevation profile of the roadway, there are concerns about using current practices for estimating roughness of low-speed and urban roads. Because of the unique features of low-speed and urban roads, research was needed to identify or, if necessary, develop means for appropriately measuring, characterizing and reporting pavement roughness of these roads. National Cooperative Highway Research Program (NCHRP) Research Report 914: Measuring, Characterizing, and Reporting Pavement Roughness of Low-Speed and Urban Roads reviews the practices for roughness measurement and the unique features of urban and low-speed roadways, and it evaluates the use of existing inertial profilers for such measurements. The report also proposes revisions to American Association of State Highway and Transportation Officials standard specifications and practices addressing inertial profiler certification and operations.