AASHTO MP 14-08
WIM system pavement smoothness is characterized by the output of a Class I profiler collecting data at 25 mm [1 in.] intervals. The data produced by such a profiler will approximate the actual perpendicular deviation of the pavement surface from an established horizontal reference parallel to the lane direction in the wheel tracks.The specification requires field collection of pavement profile information of a WIM System or of a candidate WIM site. Computer software is then used to calculate indices of long- and short-range pavement surface roughness that have been correlated to distributions of tandem axle and gross vehicle weight error levels through extensive simulations of truck dynamic loading over measured profiles. Acceptable index levels are based on ensuring to a 95 percent level of confidence that the WIM System roughness will not produce errors that exceed the tolerance level limits recommended by ASTM.
The profiler test vehicle, as well as all attachments to it, shall comply with all applicable state and federal laws. Necessary precautions imposed by laws and regulations, as well as vehicle manufacturers, shall be taken to ensure the safety of operating personnel and other traffic.
Keywords: MP014-08-UL