Federal Aviation Administration (FAA) standards regulate airport surface roughness during construction by limiting vertical changes in the slope (or grade) of new runways and taxiways in the transverse and longitudinal directions, but the FAA lacks a reliable method to determine when a pavement is too rough to use. This study recommends parameters and index values for new roughness standards for in service pavements. Pilots used an aircraft simulator to rate the roughness of Boeing B-737 and Airbus A-330 aircraft on pavement profiles collected from various airports. Acceleration indexes from the simulator results were correlated to the roughness indexes of the pavement profiles. Weighted root mean square acceleration (WtRMS) is the recommended parameter for developing the new roughness indices. Separate models are recommended for taxiways and runways. For runways, the existing roughness indices correlated well to WtRMS when the crest factor was less than 9. The average Boeing bump index (BBI) correlated best and should be used for runway roughness index development. For taxiways, all indices except BBI correlated well with WtRMS. Any of the existing indexes except BBI could be used with the WtRMS for taxiway roughness index development.

DOT/FAA/TC-21/39 Authors: Anthony Kuncas and Biqing Sheng