Comparison of Laser-Based and Sand Patch Measurements of Pavement Surface Macrotexture

This study compares the results of two measurement methods for pavement surface macrotexture: the ASTM E965 sand patch volumetric method and the Digital Surface Roughness Meter (DSRM, laser technique) conducted at a total of 13 different paved road sites in metropolitan Clark County, Nevada. Least-squares regression of DSRM-measured mean profile depth (MPD) on sand patch mean texture depth (MTD) was statistically significant (r2=0.95, p<0.05), with DSRM estimates within 0.1 mm of sand patch in 58 of 61 cases. The magnitude of the DSRM coefficient of determination was similar to that reported by previous writers for the laser Circular Track Meter.