Implementing Traffic Speed Deflection Measurements for Network Level Pavement Management in Virginia

Abstract

This paper investigates the possibility of using pavement deflection measurements obtained from a traffic speed deflectometer (TSD) for network-level structural evaluation on bituminous pavements in Virginia. Virginia currently uses falling weight deflectometer (FWD) measurements for network-level pavement management decision making for their interstate roads. Two factors were deemed important to determine if FWD data can be replaced with TSD data: (1) the distribution of effective structural number (SNeff) calculated from TSD measurements compared with SNeff calculated from FWD measurements; and (2) the consistency of TSD with FWD in identifying the same weak sections. The results show that the distribution of the SNeff from the measurements from the two devices was similar and the calculated consistency in identifying weak sections between the TSD SNeff and the FWD SNeff was higher than the consistency between the SNeff from two repeated sets of FWD measurements. This suggests that the structural condition obtained from the TSD can be used to replace the structural condition obtained from the FWD currently used in the Virginia Department of Transportation Pavement Management System. The study also assessed whether the choice of the structural index calculated with TSD measurements could potentially have a significant impact on the network-level decision-making process. Very little practical difference was observed between using the SNeff or SCI300 to identify structurally weak sections from TSD measurements. Similar analysis can be performed by other states to incorporate TSD structural conditions into their pavement management decision-making process.