Evaluating the Potential Use of Traffic Speed Deflection Device-Based Pavement Structural Data for Asphalt Pavements in VDOT’s Pavement Management Processes

About the report:

This report describes the evaluation of a proposed approach to incorporate structural condition information obtained from a traffic speed deflection device into the Virginia Department of Transportation (VDOT) pavement management system’s pavement treatment selection process for asphalt pavement sections, which are denoted within the VDOT pavement management system as BIT for bituminous. This study analyzed a subset of the more than 7,000 lane miles tested in Virginia. The subset of data includes the structural condition data on approximately 4,250 lane miles (approximately 1,690 and 2,560 lane miles on the interstate and primary networks, respectively) of the VDOT network. The proposed approach calculates the pavement effective structural number and uses this number to determine the remaining structural life (RSTL). Researchers used RSTL thresholds to determine a structural modified recommended treatment category, that is, the recommended pavement rehabilitation category based on currently used surface condition and adding in the structural condition.

Work performed by Katicha et al. (2020) showed that, for sections having the same pavement surface age, those sections in worse structural condition also had more visible surface distresses, as assessed by the load-related distress index, non-load-related distress index, and critical condition index. This shows that the structural condition influences the pavement performance and validates the need to include the structural condition in the treatment selection process. Analysis of the 2017 data collected during this study (a small subset of VDOT’s entire network) shows that about 10% of the primary network had a RSTL of less than 5 years, another 10% of the primary network had a RSTL between 5 and 12 years, and the remaining 80% of the primary network had a RSTL greater than 12 years. On the interstate network, more than 82% of the network has a RSTL of 20 years or more.

The research team performed an unconstrained needs analysis and documented case studies. The unconstrained needs analysis was performed on those sections tested in 2017 that included most of VDOT’s interstate network and portions of US 460, US 360, US 58, US 17, and US 29 (northbound only) on VDOT’s primary network. The analysis showed the difference in needs resulting from using the currently used surface-based condition and the structural modified recommended treatment category where the structural condition was added. Detailed case studies were performed for US 29 (northbound only) from Lynchburg to Charlottesville, Interstate 64 (eastbound only) from the West Virginia border to the Interstate 81 intersection, and Interstate 95 (northbound only) from north of Richmond to Interstate 495. In addition, the research team presented proposed modifications to the Detailed Pavement Condition (Jasper) Report.

_{Disclaimer Statement:The contents of this report reflect the views of the author(s), who is responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the Virginia Department of Transportation, the Commonwealth Transportation Board, or the Federal Highway Administration. This report does not constitute a standard, specification, or regulation. Any inclusion of manufacturer names, trade names, or trademarks is for identification purposes only and is not to be considered an endorsement.}

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