Performance-Based Pavement Warranty Practices (2020)

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75 Pavement warranties were common in the United States in the early 1900s and 1950s, and came back into favor during the 1990s. Meanwhile, several European (and other) agencies have had success with pavement warranties for more than six decades. At least in the United States, there is no national pavement warranty standard; therefore, agencies have developed their own specifications with varying criteria in terms of project selection criteria, warranty type, length of warranty period, risk allocation items, performance evaluation methods, and enforcement methods. The objective of this synthesis is to document highway agency practices associated with the use of performance-based pavement warranties, focusing on asphalt, concrete, and composite pavement projects (new, preservation, and rehabilitation) with warranty periods of at least 1 year. This synthesis is based on the results of a literature review, a survey of U.S. SHAs and Canadian provincial and territorial governments, and follow-up questions with agencies who indicated current use of performance-based pavement warranties. Overall Findings Agencies use two types of pavement warranties: materials and workmanship and perfor- mance. The materials and workmanship warranties typically have a duration of 1 to 2 years and require the contractor to repair defects directly within the contractor’s control. Performance warranties, on the other hand, typically have durations ranging from 2 to 20 years, with 1 to 3 years for pavement preservation, 3 to 5 years for asphalt pavements, 5 to 10 years for concrete pavements, and 20 or more years for long-term warranties as part of a P3 project. Performance warranties require the contractor to maintain the pavement according to specific performance indicators (e.g., IRI, rut, cracking, faulting) and threshold limits. In the event of distress, performance warranties also include remedial actions by which the contractor must (or recommend alternatives) conduct to repair the presence of distress. Although pavement warranty specifications can vary by agency, several components are common, including project description, warranty bond coverage, amount, effective date, pave- ment performance criteria, maintenance responsibilities of agency and contractor, dispute reso- lution team, acceptance criteria, method of measurement, and basis of payment. In a survey of U.S. SHAs, as well as all Canadian provincial and territorial transportation agencies, agencies were asked to respond to questions related to pavement warranty implemen- tation. Of the 50 responding agencies, 17 agencies indicated they have never used pavement warranties; 14 agencies used pavement warranties in the past, but no longer use them today; C H A P T E R 5 Conclusions

76 Performance-Based Pavement Warranty Practices one agency indicated not using pavement warranties in the past, but using them today; and finally, 18 agencies indicated using pavement warranties in the past as well as today. For agencies that currently use pavement warranties, project selection criteria are primarily based on pavement construction type: new, reconstructed, rehabilitation, and/or preservation. These agencies also identified using pavement management system data and engineering judgment as the primary source for determining performance indicators and threshold limits. Agencies have overcome challenges with pavement condition assessment, defining threshold values, and contractor’s resistance to the use of pavement warranties. Overcoming these challenges has provided benefits related to transferring more of the project risk to the contractor, reducing pavement failures, improving workmanship, and improving pavement performance. Case examples highlighting pavement warranty specifications for Alberta Transportation, FDOT, MDOT, PennDOT, and WVDOH were also provided. The case examples summarized agency practices related to project selection criteria, dispute resolution, pavement inspection, and individual pavement warranty specifications. The case examples included warranties for a variety of pavement types including new and reconstructed asphalt and concrete pavements, asphalt pavement rehabilitation (primarily overlays), and pavement preservation (e.g., crack sealing, seal coats, microsurfacing, and thin overlays). Suggestions for Future Research The following presents suggested future research related to performance-based pavement warranties. • U.S. domestic scan. Suggest conducting a domestic scan of agencies currently using pave- ment performance warranties to document agency-specific implementation practices. Includ- ing but not limited to, time commitment for conducting and monitoring warranty projects, agency testing requirements, and dispute resolution challenges and outcomes. • Application of pavement warranties post original construction. Agency specifications typi- cally include clauses requiring pavements to be constructed, for example, true to established cross-section and grade, material properties, and layer thickness. Specifications also include provisions on how to address deficient sections: for example, do nothing, assess a penalty based on percent of work, or remove and replace. Another option that is not well documented (and beyond the scope of this synthesis) includes the application of agency- or contractor- recommended treatments to address original construction deficiencies that also include a warranty specification. While the applied warranty would meet the procedures and practices described in this synthesis, this research would: – Determine impacts of remedial action (do nothing, impose penalty, treatment application) beyond remove and replace. – Summarize potential treatment applications dependent on as-constructed conditions. – Develop guidelines on when to require a warranty on remedial treatments. – Provide examples (including contractual requirements) of agencies who have success- fully applied remedial treatment warranties after completion of the original pavement construction. • Framework for defining performance thresholds and warranty periods. Research could be initiated to develop a framework to assist agencies in determining performance thresh- olds and warranty periods by project type (e.g., preservation, rehabilitation, reconstruction). Potential tasks include identifying data sources and data elements, evaluation methods, criteria considerations, and steps for obtaining consensus and buy-in. • Determine cost and performance impacts of pavement warranties. During the follow-up questions, only one agency provided information quantifying the impact of warranties on the

Conclusions 77 cost of pavement construction (and only for a limited number of projects), and none of the responding agencies were provided details on how warranties have impacted pavement per- formance. This research effort would quantify both project cost and pavement performance as a result of pavement warranty specifications. The task for identifying cost impacts would quantify costs for both warranty and nonwarranty projects, compare estimates, and deter- mine the cost impacts of pavement warranties. The pavement performance task would obtain historical pavement performance data on both warrantied and nonwarrantied pavements, develop a process to quantify changes in performance (considering, for example, impacts of climate and truck loadings, pavement design), and quantify changes in pavement perfor- mance from warranties. • Detailed evaluation of pavement warranties. This research effort would identify, select, evaluate, monitor, and analyze various pavement warranties across the United States. Similar to the LTPP study, this research effort would track design, construction, and pavement performance, as a minimum, over the life of the pavement warranty period. Documenting design and construction efforts, materials testing results, and initial and longer-term per- formance monitoring, warranty projects would be selected based on, for example, climatic location, pavement type (treatment) selection, and truck traffic loading, to evaluate a broad range of applications. Results of this project would quantify pavement warranties in relation to the contractor’s ability to meet agency construction specifications, cost assessment (both in relation to contractor and agency), and performance over the warranty period.