NCDOT Quality Control Methods for Weigh-in-Motion Data

Abstract

At hundreds of weigh-in-motion (WIM) stations, state departments of transportation (DOTs) collect WIM data 24/7 to meet federal traffic reporting requirements. The North Carolina Department of Transportation (NCDOT) collects WIM data using procedures consistent with recommended industry practices to estimate static vehicle axle weights based on dynamic traffic measurements. Data errors and poor quality data are captured regardless of the technology used, and a quality control (QC) process is an important part of all WIM data systems. WIM data must undergo a series of sequential and well-defined QC procedures to ensure that the data meet the federal requirements and new standards for the Mechanistic Empirical Pavement Design Guide (MEPDG) process. This article documents the NCDOT WIM QC procedures. The results of the QC analysis provide reliable data sets for use in developing Levels 1, 2, and 3 traffic data inputs for the North Carolina MEPDG models.