High Value Research Sweet Sixteen AASHTORACTRB State Representatives

High Value Research Sweet Sixteen AASHTO‐RAC/TRB State Representatives Annual Meeting July 24, 2018 Ranking of Pavement Preservation Methods and Practices Terry Swygert South Carolina Department of Transportation Research conducted by Clemson University Principal Investigator Brad Putman, Ph. D, Associate Professor

Background SCDOT maintains a roadway network consisting of 90, 598 lane-miles (41, 377 centerline miles ) which is the 4 th largest state‐maintained highway system in the nation. SCDOT maintains 63% of the state’s public roads. Interstate; 3, 795 Non-Federal Aid Secondary; 41, 393 Primary; 23, 983 Federal Aid Secondary; 21, 427 SCDOT System (90, 598 lane‐miles) 2

Objective The objective was to identify methods to improve the implementation of pavement preservation strategies on asphalt concrete roadways in SC with specific attention to pavements in the Non-Federal Aid Secondary system. 3

Pavement Preservation Program To sum up the objective of a pavement preservation program, it is deciding on “the right treatment on the right pavement at the right time. ” 4

Study Tasks To accomplish the objective, the scope of this study included the following tasks: Ø Conduct a literature review to compile basic and detailed information about pavement preservation and practices. Ø Conduct a survey of SCDOT pavement preservation practices across the state. Ø Evaluate methods to determine appropriate timing of pavement preservation treatments and identification of preservation candidates. Ø Develop a decision support tool to support pavement preservation treatment selection and timing. Ø Identify data elements that should be recorded to track the performance of pavement preservation treatments in South Carolina. Ø Identify economic benefits of pavement preservation treatments. 5

Findings The research identified five areas to help SCDOT increase the effectiveness of its pavement preservation program by: 1. Include more educational opportunities for decision makers related to pavement preservation to focus on long-term network preservation and planning. 2. Consider implementing the decision support concept based on Remaining Service Life to continuously increase the number of lane-mile -years included in the pavement preservation candidate pool (i. e. , PQI ≥ 3. 0). 3. Document additional information on preservation treatments to adequately track pavement preservation treatments. 6

Findings 4. Implement a more detailed pavement condition evaluation protocol to monitor the actual life extension of pavement preservation treatments. This process should include pre- and posttreatment condition assessment followed by routine evaluations on an annual basis. 5. Consider implementing the system to quantify the benefit-cost ratio of pavement preservation treatments to better understand the effectiveness of different treatments in particular situations. 7

Implementation SCDOT Maintenance Office has taken great strides to implement these findings including the following: Ø More Educational Opportunities Evaluation protocols and cost-benefits of preservation treatments will be offered this fall in Pavement Preservation Level II training utilizing newly developed tools from this research project (i. e. , the Pavement Preservation Treatment Selection worksheet and Pavement Preservation Treatment Benefit-Cost analysis tool). 8

Implementation Ø Implementing the Decision Support Concept based on Remaining Service Life The Director of Maintenance Office has established a Preservation Pool of Candidates report through the Department’s Intelligent Transportation Management application identifying segments with PQI’s >= 3. 2 & <=4. 0. The reporting feature should aid field personnel with project selection by using a targeted approach to determine routes eligible for various pavement preservation treatments. 9

Implementation Ø Better Assessment of Treatment Options that takes Costs and Benefits into account Implementation efforts are now underway, with a detailed analysis of various roadway treatments—chip seals, microsurfacing, and ultrathin lift overlays—that will feed into and improve the agency’s pavement management system and decision-making tools. 10

SCDOT Strategic Plan Lastly, this research project directly aligns and supports the 2 nd Goal of the SCDOT Strategic Plan 2018 -2020 for maintaining and preserving the existing transportation infrastructure. This study has provided SCDOT with a clear direction for a strategic and targeted approach to identify and place the right treatment on the right road at the right time. 11

For more information, contact: Dr. Bradley J. Putman Professor of Civil Engineering Clemson University at putman@clemson. edu 12 A copy of the final report is available at the SCDOT Research Website located at http: //scdot. scltap. org/