This workshop gathers leading international figures in the field of traffic speed deflection testing for use in network-level pavement management system applications. Presenters will address (a) the need for technology to support the decision-making process with a leading—not lagging—indicator, (b) findings from recent research throughout the world, (c) the readiness of devices, and (d) recent successful technology implementations. This workshop is an important step toward the advancement of pavement engineering technology with a focus on the decision-making process.
Nondestructive deflection testing for the structural evaluation of pavements has been around for decades and falling weight deflectometers (FWDs) represent the state of the practice for project level application but have shortcomings for network level applications, testing speed being one of them. Several organizations in the United States and Europe have worked on the development of moving pavement deflection testing devices and, in the last decade, traffic speed deflection devices (TSDD) have become a reality. The viability of TSDDs spurred several research efforts to assess, validate and develop analysis methodologies to advance their use in network level pavement structural evaluation and pavement management applications. This presentation provides an overview of the many TSDD-related research efforts in the US in the last decade and highlights key findings from those efforts.
Structural condition data are commonly collected at the project level using Falling Weight Deflectometer (FWD) measurements. However, the stop and go process necessitates traffic control to ensure drivers and workers’ safety, which limits the use of FWD at the network level. Recent developments in Traffic Speed Deflection Devices (TSDD) have offered the potential to characterize pavement structural conditions at the network level. Louisiana conducted a comprehensive evaluation of the Rolling Wheel Deflectometer (RWD) and the Traffic Speed Deflectometer (TSD). This presentation demonstrates the capability of these devices to distinguish between structurally deficient and structurally sound pavements in addition to measurements’ repeatability. In addition, it presents a framework for incorporating pavement structural conditions into the Louisiana Pavement Management System (PMS) decision matrix at the network level. The cost-effectiveness of the technology will also be discussed.
Idaho Transportation Department (ITD) along with Infrasense and NCE have been using Traffic Speed Deflectometer (TSD) and Ground Penetrating Radar (GPR) for the past three years to perform corridor studies on a total of 1,218 miles of pavement. This work included determining the thickness and stiffness of pavement layers, and in combination with traffic forecasts, pavement distress and roughness data predicting remaining life and overlay requirements. All work was performed at the TSD’s reporting interval of 0.01 miles, allowing for consideration of far greater spatial variability than was possible using previous data collection techniques. The results were uploaded into a GIS database, and are being used to identify, prioritize and estimate the cost of future 3R projects.