@article{ref1,
title="Indicators of longitudinal unevenness of roads in the USA",
journal="International journal of vehicle design",
year="2008",
author="Kropac, Oldrich and Mucka, Peter",
volume="46",
number="4",
pages="393-415",
abstract="About 25,800 longitudinal profiles of in-service roads in the USA (Long-Term Pavement Performance (LTPP) Program) were evaluated to obtain indicators of the longitudinal unevenness (roughness) of the road surface defined by standards ISO 8608 : 1995 and EN 13036-5 : 2006. Besides the commonly used International Roughness Index (IRI), also parameters of the Power Spectral Density (PSD) were evaluated taking into account not only the whole interval of effectively acting wavelengths, but also its two and three partial sub-bands. Differences between left and right tracks and between Asphalt Concrete (AC) and Portland Cement Concrete (CC) wearing courses were considered. For all the mentioned indicators (21), their Probability Density Functions (PDF) and numerical statistics were estimated.<p />",
language="en",
issn="0143-3369",
doi="10.1504/IJVD.2008.020306",
url="http://dx.doi.org/10.1504/IJVD.2008.020306"
}