AASHTO R 48-08

This practice describes a method for estimating rut depth in pavement surfaces from transverse profile measurements. Five transverse profile points are the minimum number of points required to determine rut depth. While this practice is based on a five-measurement transverse profile, more than five measurements greatly improves the accuracy and enhances the likelihood of identifying the maximum rut depth given survey vehicle wander and various rut configurations.Note--A rut is a longitudinal surface depression in the wheelpath(s) of a pavement surface measured between the width limits of the lane.Procedures are defined for measuring a transverse profile and deriving a rut depth, but detailed specifications are not included for equipment, instruments, or software used to make the measurements. Any equipment and/or procedure, which can measure as specified, with the accuracy stipulated herein and which can be adequately calibrated, is acceptable for this method.