Raleigh, NC, United States
Raleigh, NC, United States

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Zimmerman K.A.,Applied Pavement Technology Inc. | Corley-Lay J.,Pavement Management Unit | Wlaschin J.B.,FHWA | Tetreault R.M.,Vermont Agency of Transportation
Transportation Research Record | Year: 2013

Nine pavement and asset managers from the United States participated in the International Scan on Managing Pavements and Monitoring Performance. The scan team sought input on processes for implementing sustainable performance-based programs; effective communication methods for garnering upper management and legislative support; agency cultures that support performance-based programs; and techniques, tools, analyses, and reporting that support performance-based management. The team traveled to New Zealand, Australia, Sweden, the Netherlands, and England and gathered information from 14 agencies. The agencies selected for consultation had experience with managing their pavement networks under constrained budgets. Although the initial focus of the scan was on pavement management, the team found that some of the agencies conducted pavement management within an asset management framework. The findings are thus equally applicable to assets other than pavements. The key findings are (a) agency culture supports a long-term view toward managing pavements, (b) elected officials understand their responsibilities as stewards of public funds, (c) the road network is managed as a service provided to the traveling public, (d) agency priorities are known and agency personnel are held accountable for their actions, (e) the agencies recognize the importance of building internal capacity and capabilities, and (f) efficiency and value drive program delivery approaches. The scan team selected four implementation strategies for moving scan findings into practice: communicating scan findings, developing guidelines for asset management plans and long-term financial plans, encouraging use of recurring program assessments, and developing agency capabilities in the areas of engineering, contract administration, economics, and accounting.

Wang Y.,Hong Kong Polytechnic University | Wang G.,East Carolina University | Mastin N.,Pavement Management Unit
Journal of Performance of Constructed Facilities | Year: 2012

The authors investigated the effectiveness and costs of preventive treatment techniques for flexible pavements. Based on survey results from 29 state departments of transportation (DOTs), it was found that the expected pavement life extension caused by these treatments follows the order of thin hot-mix asphalt (HMA) overlay, microsurfacing tied with chip sealing, slurry sealing, and crack filling/sealing. The reported costs follow the order of thin overlay, microsurfacing, and chip sealing tied with slurry sealing, whereas costs of crack sealing/filling cannot be directly compared. The authors also analyzed data from 81 Long-Term Pavement Performance (LTPP) program specific pavement studies (SPS) experiments, which were specifically designed and constructed to study the effectiveness of pavement treatments. Based on paired t-tests, it was found that all the treatments reduced international roughness index (IRI) with statistical significance. The authors then pooled the data from all the control sections and created a pseudo control section and subsequently developed a linear regression model for it. By comparing the effects of treatments with this pseudo control section, the authors found that the approximate life extension of the pavement sections benefited from these treatments is as follows: thin overlay for 5.4 years, chip sealing for 1.9 years, crack sealing for 1.7 years, and slurry sealing for 1.1 years. © 2012 American Society of Civil Engineers.

Chen D.,University of North Carolina at Charlotte | Cavalline T.,University of North Carolina at Charlotte | Mastin N.,Pavement Management Unit
Journal of Performance of Constructed Facilities | Year: 2015

This study presents a method to develop piecewise linear (PL) performance models for pavement condition data in a pavement management system (PMS). These condition data are usually ordinal and have more than two severity levels. Ordinal logistic regression is conducted to derive probabilities of each individual severity level. The intersections of probability curves are identified as the breakpoints, which can be used to develop PL models. This proposed method was then applied successfully to develop four PL models, for interstates, U.S. routes, North Carolina routes, and secondary routes, using transverse cracking condition data of flexible pavements in a state DOT's PMS. Results showed that the PL models reflected actual deterioration trends well and that the proposed method is robust. © 2014 American Society of Civil Engineers.

Corley-Lay J.,Pavement Management Unit | Jadoun F.M.,North Carolina State University | Mastin J.N.,Pavement Management Unit | Kim Y.R.,North Carolina State University
Transportation Research Record | Year: 2010

The Long-Term Pavement Performance (LTPP) program has collected pavement distresses for general pavement study (GPS) sites throughout the country. These sites were used in the initial calibration of the Mechanistic-Empirical Pavement Design Guide, so it is important for states to compare their distress identification procedures and results with the LTPP distresses as part of the local calibration process. North Carolina has 24 GPS sites, of which four are concrete, one went out of service very early, and the remainder are flexible pavements. This paper focuses on the flexible pavement distresses. The GPS sites are 500-ft sections of much longer roadways. The LTPP distress data were extracted for the North Carolina Department of Transportation (NCDOT) GPS sites. Corresponding locations and their distress histories were pulled from the NCDOT pavement management system. In addition, rut depth measurements taken by high-speed profilometer were obtained for many of the sections for comparison with LTPP rut depth measurements. As might be expected, the LTPP walking survey revealed higher amounts of distress than the NCDOT windshield survey. Alligator cracking is the major distress for NCDOT pavements, and a roughly two-to-one relationship was found between alligator cracking by LTPP compared to NCDOT. Rut depths measured by LTPP were also found to be larger than those measured by high-speed profilometer, but in either measure, rut depths measured for NCDOT sections were low (less than 10 mm for all sites).

Corley-Lay J.,Pavement Management Unit
Transportation Research Record | Year: 2014

Performance measures considered for flexible and rigid surfaced pavements and the threshold values for these measures are reported. A survey was sent to members of the Joint Technical Committee on Pavements, and 14 of 20 states responded. Performance measures for flexible pavements included international roughness index (IRI), rutting, and cracking. Performance measures for rigid pavements included IRI, patching, cracking, pop-outs, faulting, and damaged joints. For each measure, states were asked to define "good," "fair," and "poor" for both Interstates and other National Highway System routes. States were asked to define their system's performance for given thresholds and to provide some information about how they collected, processed, and used the data. States use rutting and cracking to assess performance of flexible pavements. The IRI was the third-ranked measure but was consistently applied to both flexible and rigid pavements. Rutting measurements varied with the number and types of sensors, and states used five-point sensors to line sensors to three-dimensional cameras. Use of cracking as a performance measure required consensus building about definitions, measurement methods, and thresholds. Survey responses for rigid pavements were limited to jointed plain concrete because 12 of the 14 states indicated that the majority of their rigid pavements were of this type. Additional work is required for a faulting measure, because the ability to detect the joint is a function of the distance between consecutive traces. Development of definitions, methods, and thresholds is required for other rigid pavement performance measures, including patching, cracked slabs, and damaged joints.

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