Pavement Management System Data Research Articles

Methodology to Improve the AASHTO Subgrade Resilient Modulus Equation for Network-Level Use

AbstractFalling weight deflectometer (FWD) testing is commonly used to estimate subgrade resilient modulus (MR) by using back calculation and/or the AASHTO MR equation. Considering the availability of limited information in the pavement management information system (PMIS) database, the AASHTO MR approach is suitable for subgrade assessment at a network level because of its simplicity. An adjustment factor is commonly applied to the AASHTO MR equation because of the difference between laboratory-measured MR and estimated MR. However, large variations in the adjustment factor have been observed with different geographical locations and climate conditions. Thus, using a fixed value of the adjustment factor has led to inaccurate assessment of subgrade soil MR. This paper presents a methodology to improve the accuracy of the existing AASHTO MR equation by constructing an MR adjustment factor based on the correlation of back-calculated ER and AASHTO MR. This study also investigated the effects of subgrade soil...

Development of Piecewise Linear Performance Models for Flexible Pavements Using PMS Data

AbstractThis 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.

Threshold Values of Performance Indicators for Asphalt Concrete Pavement to Apply to Pavement Performance Warranty

Abstract The performance warranty system is quite innovative in requiring a contractor’s warranty for pavement performance over a certain period of time. European countries adopted performance warranty systems about 40 years ago. The United States adopted this system in the early 1990s to improve construction quality and performance, as well as to reduce life cycle cost. In Korea, for the purpose of resolving construction management and quality control problems and poor construction, the performance warranty system is considered as part of the solution. The appropriate performance indicators, reasonable threshold values, and warranty periods have to be selected in order to adopt a performance warranty system that requires keeping the pavement performance above a certain level of satisfaction for the warranty period. For this reason, structural, functional, and safety performance were defined first, and then rut depth, roughness, and crack ratio were selected as performance warranty indicators. For the purpose of suggesting performance warranty threshold values that reflect domestic circumstances, pavement management system data were surveyed, a special project was conducted, and a total of 888 sample sections were analyzed. A threshold level at 95 % of each indicator’s distress was determined for the threshold value; this prevents the worst 5 % of poor performance cases. A 14-mm rut depth, 3.6 m/km International Roughness Index, and 20 % crack ratio for five years were selected as threshold values. To avoid early deterioration of pavement, three- to five-year warranty periods are suggested.

Utilizing Asphaltic Concrete Overlay to Mitigate the Detrimental Effects of Alkali Carbonate Reactions in Portland cement Concrete Pavement

In 1990, the Louisiana Department of Transportation and Development (LADOTD) constructed approximately 9.96 km of portland cement concrete (PCC) pavement on Interstate 20. In 1994, the PCC began to show signs of distress in the form of surface cracks, joint spalling, pop outs, and efflorescence. Alkali carbonate reactions (ACR) in the PCC were discovered upon analyzing cores taken from the PCC in 1996. In 1997 and 1998, LADOTD placed a 102-mm AC overlay on the PCC pavement on the east- and west-bound lanes, respectively. Sawing and sealing the AC over the PCC joints was performed to mitigate reflective cracking. The AC overlay added structure to the pavement section reducing stress on the PCC, created a barrier preventing surface moisture from entering into the PCC, and created a thermally insulated pavement reducing the temperature within the PCC. Pavement surface distress data was obtained by data mining the LADOTD Pavement Management system data base and structural testing the composite pavement was conducted with the Falling Weight Deflectometer. Cores were obtained from the PCC and tested in accordance with a modified ASTM C1567-13 in October 2012. Approximately 15 years after the placement of the AC overlay, only minimal transverse cracking, longitudinal cracking, and patching were discovered and the roadway had a smooth ride. Results from the structural testing indicated that the PCC pavement was distressed with the overall structural number of the pavement being approximately 5.5. When tested in accordance with a modified ASTM C1567-13, significant volumetric strains up to 0.8 percent were measured on the PCC cores. Volumetric strains of that magnitude will cause detrimental effects on the PCC, eventually leading to its destruction.

Safety Impact of Pavement Conditions

Pavement condition has been known as a key factor related to ride quality, but it is less clear how pavement condition is related to traffic crashes. The researchers used a geographic information system to link data from the Texas Department of Transportation crash record information system and the pavement management information system. Linking the data provided an opportunity to examine in depth the impact of pavement conditions on traffic crashes. This study analyzed the correlation between four key pavement condition scores and crash rates on a large number of crashes on Texas asphalt nonfreeway roadways between 2008 and 2009. The results overwhelmingly suggest that very good pavement conditions coincide with much lower crash rates compared with very poor conditions. The findings of this study provide insights into how pavement conditions might affect crash rates on different types of roadways. The study also provides critical knowledge that may lead to improvements in safety-oriented pavement design. Because of funding shortages, many state roadways suffer severe pavement deterioration, which may result in increased crash rates, as this study suggests. The findings of this study serve as scientific justification for more adequate maintenance of roadways to avoid further safety deterioration. The researchers recommend that state highway agencies maintain fair or good pavement conditions, at a minimum, on all major state highways. When possible, very good pavement conditions should be maintained to reduce crashes.

Evaluation of MEPDG flexible pavement design using pavement management system data: Louisiana experience

This paper presents a recent study on using the mechanistic–empirical pavement design guide (MEPDG) design software (version 1.1) to evaluate the performance of typical Louisiana flexible pavement structures and compared it to the existing pavement performance data available in the pavement management system. The pavement performance indicators evaluated in this study include fatigue cracking, rutting and International Roughness Index (IRI). In addition to comparing the measured and predicted mean performance, the predicted pavement distresses at certain reliability design levels were also compared with the field variation of distresses extracted from a number of selected projects. The overall comparison results between the measured and predicted pavement distresses showed strong dependency on the pavement structure type considered in this study. Generally speaking, the MEPDG rutting models tended to over-predict the total rutting for Louisiana flexible pavements, whereas both fatigue cracking and IRI models in the MEPDG seemed to be adequate for most projects selected. Finally, a special optimisation approach was introduced to determine a set of preliminary local calibration factors for the MEPDG rutting models for two types of flexible pavements in Louisiana.

Impact of pavement conditions on crash severity

Pavement condition has been known as a key factor related to ride quality, but it is less clear how exactly pavement conditions are related to traffic crashes. The researchers used Geographic Information System (GIS) to link Texas Department of Transportation (TxDOT) Crash Record Information System (CRIS) data and Pavement Management Information System (PMIS) data, which provided an opportunity to examine the impact of pavement conditions on traffic crashes in depth. The study analyzed the correlation between several key pavement condition ratings or scores and crash severity based on a large number of crashes in Texas between 2008 and 2009. The results in general suggested that poor pavement condition scores and ratings were associated with proportionally more severe crashes, but very poor pavement conditions were actually associated with less severe crashes. Very good pavement conditions might induce speeding behaviors and therefore could have caused more severe crashes, especially on non-freeway arterials and during favorable driving conditions. In addition, the results showed that the effects of pavement conditions on crash severity were more evident for passenger vehicles than for commercial vehicles. These results provide insights on how pavement conditions may have contributed to crashes, which may be valuable for safety improvement during pavement design and maintenance. Readers should notice that, although the study found statistically significant effects of pavement variables on crash severity, the effects were rather minor in reality as suggested by frequency analyses.

Hybrid Technique for Calibrating Network-Level Performance Models of Continuously Reinforced Concrete Pavements

Pavement performance models exist in various forms to cater to the pavement management agencies’ needs and resources. Well-calibrated models are needed to accurately predict future pavement conditions and to forecast and prioritize confidently the future rehabilitation and maintenance expenditures. Statistical tools are commonly used to develop the performance models. These statistical models may be impractical or misleading if they do not consider experts’ opinions. This paper presents a hybrid technique where statistical tools and expert knowledge are combined for the calibration of pavement performance models. This technique was validated using historical pavement condition data for continuously reinforced concrete pavements (CRCP) from the Texas Department of Transportation’s pavement management information system (TxDOT-PMIS). The recalibrated CRCP performance models obtained with the hybrid technique represent an improvement when compared to the current models since they merge expert opinion and statistical analysis, which better reflect field observations regarding distress initiation, distress evolution rate, and maximum allowable amount of distress growth.

Use of Structural Condition Index for Pavement Structural Evaluation Tool

Abstract In this study, an effort was made to evaluate pavement condition using the pavement structural condition index (SCI), which isbased on falling weigh deflectometer (FWD) deflection basin and structural numbers that incorporated various levels of traffic andsubgrade resilient modulus. Extensive field validations were conducted to assess the effectiveness of SCI along with comparisonof pavement distress and condition score restored in the Pavement Management Information System (PMIS). The analysis resultsrevealed that the SCI appears to realistically capture the existing pavement condition compared to the pavement scores and fieldsurvey results. Based on this finding, probabilistic and deterministic models were developed to estimate SCI when FWD data isnot available. These models are deemed most useful for network-level analysis purposes to aid establish pavement maintenanceand rehabilitation plans.Key words: Falling weigh deflectometer deflection basin, Pavement structural condition index, Pavement management informationsystem, Probabilistic and deterministic models, Subgrade resilient modulus

Development of Texture Measurement System Based on Continuous Profiles from Three-Dimensional Scanning System

Pavement texture is an important indicator of road serviceability. Pavement texture is directly linked to pavement and tire skid resistance and to traffic safety for the public. Therefore, most transportation agencies require texture data for their pavement management information systems. Current methods for measuring pavement texture that use high-speed distance sensors or three-dimensional line scan devices have shown limitations for data stability. Problems caused by vehicle vibration, bad data from optical sensors, and, most important, speed dependency related to the sensor sampling time or exposure time either make the texture results unreliable or reveal noticeable errors. The influence of speed on network-level texture data collection was studied, and a highspeed, high-precision three-dimensional texture system was developed. The experiment confirmed that improper selection of a sensor with large exposure time would result in speed dependency on measured texture data. Because the system developed in the study adopted a very small exposure time for each sampling, it could produce accurate texture data that are largely independent of vehicle speed.

Development of Network-Level Project Screening Methods Supporting the 4-Year Pavement Management Plan in Texas

AbstractThe Texas DOT (TXDOT) is concerned about the widening gap between pavement preservation needs and available funding. Thus, the TXDOT Austin district pavement engineer (DPE) has investigated methods to strategically allocate available pavement funding to potential projects that improve the overall performance of the district and Texas highway systems. The primary objective of the study presented in this paper is to develop a network-level project-screening and ranking method that supports the Austin district 4-year pavement-management plan development. The writers developed candidate-project selection and ranking algorithms that evaluated pavement conditions of each project candidate using data contained in the Pavement Management Information System (PMIS) database, incorporated insights from Austin district pavement experts, and implemented the developed method and supporting algorithm. This process previously required weeks to complete, but now requires about 10 min, including data preparation an...

Development of the Triangular Model for Pavement Evaluation Using the Rolling Wheel Deflectometer

Using the rolling wheel deflectometer (RWD), which measures pavement deflections at traffic speeds, offers the potential to characterize the structural capacity of the road network without major delays and to do so in a cost-effective way. To optimize using the RWD at the network level, an assessment tool is needed to incorporate RWD data into a current pavement management system (PMS) and to identify pavements in need of maintenance or rehabilitation. The objective of this study is to present the development of a screening tool, referred to as the pavement-assessment triangular model, to predict overall pavement conditions on the basis of RWD deflection, roughness measurements, and surface conditions as described by a pavement condition index (PCI). Formulation of the proposed tool and its application were based on data collected during evaluation and testing of RWDs in Louisiana. This screening tool may be used at the network level to identify sites in poor condition and to conduct additional testing using the falling weight deflectometer (FWD) on the identified sites or to select a rehabilitation treatment option based on RWD measurements and PMS data.

Texas Department of Transportation 3D Transverse Profiling System for High-Speed Rut Measurement

Pavement rutting is a critical measure of road condition. Severe rutting indicates road structure deformation and exposes drivers to hazards, especially when it holds rainwater. The Pavement Management Information System requires ruts to be measured regularly for pavement condition score calculation. In the past few decades, a number of automated rut-measurement devices have been developed and used for highway speed data collection. However, all these devices exhibit limitations on measuring ground truth in practice. This paper introduces a high-speed true three-dimensional (3D) pavement surface measurement tool that can produce accurate rut data at highway speeds. Network-level data collections were conducted and the results analyzed to evaluate and verify the system.

Network‐Level Road Pavement Maintenance and Rehabilitation Scheduling for Optimal Performance Improvement and Budget Utilization

Abstract: This article discusses how to efficiently and completely solve a bi‐objective pavement maintenance and rehabilitation‐scheduling problem, which aims at optimizing two objectives of pavement condition improvement and budget utilization in a simultaneous manner. This problem may be addressed by the weighting method, constraint method, ranking method, and various metaheuristic methods. However, none of these methods can guarantee the complete Pareto‐optimal solution set, which would potentially lead to suboptimal decisions. In this article, a parametric method is suggested to solve the bi‐objective pavement maintenance and rehabilitation‐scheduling problem. The effectiveness and efficiency of the parametric method is investigated and demonstrated through a case study using the real‐world data set from the Dallas District's Pavement Management Information System. A performance comparison between the widely used weighting method and the parametric method clearly justifies the computational advantages of the parametric method.

Calibration of the Mechanistic–Empirical Pavement Design Guidefor Flexible Pavement Design in Arkansas

Because of potential differences between national and local conditions, the Mechanistic–Empirical Pavement Design Guide (MEPDG) should be calibrated to a local level. Arkansas has invested heavily in efforts to implement the MEPDG. This paper summarizes the initial local calibration of flexible pavement models in the MEPDG for Arkansas. Data from the Long-Term Pavement Performance (LTPP) database and local pavement management system (PMS) were used. The solver function in Microsoft Excel was used to optimize the coefficients for alligator cracking. Iterative runs of the MEPDG by means of discrete calibration coefficients were conducted to optimize rutting models. In general, the alligator cracking and rutting models are improved by calibration. However, a question remains about the suitability of the calibrated models for routine design. Many default values were used in the MEPDG because of a lack of data. It is recommended that additional sites be established and a more robust data collection procedure be implemented for future calibration efforts. The difference in the definitions of transverse cracking between the MEPDG and the LTPP may be critical to data collection and identification. Thermal cracking should be specifically identified in a transverse cracking survey to calibrate the transverse cracking model in MEPDG. The procedure using LTPP and PMS data for local calibration of the MEPDG in Arkansas is established. Additional development of database software for data manipulation, preprocessing, and quality control—under way in Arkansas—will significantly streamline the calibration process.

Use of Pavement Management Information System for Verification of Mechanistic–Empirical Pavement Design Guide Performance Predictions

The performance models used in the Mechanistic–Empirical Pavement Design Guide (MEPDG) are nationally calibrated with design inputs and performance data obtained primarily from the national Long-Term Pavement Performance database. It is necessary to verify and calibrate MEPDG performance models for local highway agencies’ implementation by taking into account local materials, traffic information, and environmental conditions. This paper discusses the existing pavement management information system (PMIS) with respect to the MEPDG and the accuracy of the nationally calibrated MEPDG prediction models for Iowa highway conditions. All the available PMIS data for Interstate and primary road systems in Iowa were retrieved from the Iowa Department of Transportation (DOT) PMIS. The retrieved databases were then compared and evaluated with respect to the input requirements and outputs for Version 1.0 of the MEPDG software. Using Iowa DOT's comprehensive PMIS database, researchers selected 16 types of pavement sections across Iowa (not used for national calibration in the NCHRP 1-37A study). A database of MEPDG inputs and the actual pavement performance measures for the selected pavement sites were prepared for verification. The accuracy of the MEPDG performance models for Iowa conditions was statistically evaluated. The verification testing showed promising results in terms of MEPDG's performance prediction accuracy for Iowa conditions. Recalibrating the MEPDG performance models for Iowa conditions is recommended to improve the accuracy of pavement performance predictions.

Necessary Assessment of Use of State Pavement Management System Data in Mechanistic–Empirical Pavement Design Guide Calibration Process

Calibration and validation of the Mechanistic–Empirical Pavement Design Guide (MEPDG) for state department of transportation (DOT) networks requires detailed information for a variety of pavement inputs. The biggest database resource that most states possess is their pavement management system (PMS). It is understandable for any DOT to maximize the use of this resource to the greatest extent possible. However, before any state uses PMS data in MEPDG calibration, it is important that a careful comparison be made of the equality of the measurements, data, and so forth in the PMS database with national Long-Term Pavement Performance (LTPP) values. The purpose of this paper is to review possible differences between several key data found in a state PMS database and the LTPP database. Arizona Department of Transportation (ADOT) PMS data are used for this purpose. The specific variables examined in this paper deal with distress type (rutting, cracking, and roughness) and nondestructive deflection testing (NDT) backcalculated moduli to predict in situ pavement layer properties. It was concluded that significant differences did exist between the ADOT PMS values and LTPP measurements. Differences were found between ADOT's NDT measurements and LTPP data in rut measurements, asphalt cracking, international roughness index, and all layer backcalculated moduli. Consequently, ADOT may incur significant expense to calibrate the MEPDG to Arizona conditions. The paper discusses several possible reasons for differences between the PMS data of a specific agency and those in the LTPP database.

Costs and Benefits of Thin Surface Treatments on Bituminous Pavements in Kansas

This study investigated the benefits and costs of commonly used thin surface treatments for maintenance of bituminous pavements in Kansas. Cost and performance data were collected from the Kansas Pavement Management Information System for all treatments applied from 1992 to 2006. Results show that seal coats have a short average service life on Interstate highways. The average life on non-Interstate highways is about 4 years. This life is slightly lower than that for other thin surface treatments, including hot-mix asphalt (HMA) overlays. Seal coats also have a significantly lower equivalent uniform annual cost than do all other thin surface treatments in Kansas. A comparison of pavement benefit values before and after application showed that seal coat could not mitigate distresses better than other methods, especially thin HMA overlays. However, its performance is quite similar to that of the modified slurry seal.

Assessing the Agreement among Pavement Condition Indexes

Pavement condition indexes are numerical indicators of the structural and material integrity of a pavement. Because these indexes appear to be similar (essentially a 0–100 scale, with 100 indicating ideal condition), it can be tempting to use different indexes for comparing the performance of pavement networks in different states or jurisdictions within a state. To ascertain the level of agreement among these condition indexes, six pavement condition indexes from five DOTs in the United States are discussed and compared using distress and ride quality data obtained from the Pavement Management Information System of the Texas Department of Transportation. The computed scores were compared visually (using scatter plots) and statistically (using paired t -test). The results provide empirical evidence that there are significant differences among seemingly similar pavement condition indexes.

Long-Term Performance of Reflective Cracking Mitigation Techniques in Nevada

Hot-mix asphalt (HMA) overlay is one of the commonly used methods for rehabilitating deteriorated pavements. The Nevada Department of Transportation (DOT) uses HMA overlays as a rehabilitation technique for the majority of the state's flexible pavements. One major type of distress influencing the life of an overlay is reflective cracking. In the past, Nevada DOT has experimented with a number of techniques— such as cold in-place recycling, reinforced fabrics, stress relief courses, and mill and overlay—to reduce the impact of reflective cracking on HMA overlays. Several projects were constructed under each category. The long-term field performance of various Nevada DOT reflective cracking mitigation techniques was evaluated; the techniques were used on flexible pavements at 33 field projects. Performances of the various projects were analyzed by fatigue, transverse, and block cracking measurements from Nevada DOT's pavement management system data. In addition, the statistical approach called principal component analysis was used to asses the effectiveness of each of the reflective cracking techniques. The study indicated that cold in-place recycling and mill and overlay were the most effective treatments for reflective cracking of HMA overlays over HMA pavements under Nevada's conditions, except when the existing pavement experiences severe alligator cracking. In such situations, it is recommended that HMA pavement be subjected to reconstruction or full-depth reclamation.