Influence of Traffic Characterization Methodology on Service Life Prediction of Pavements Subjected to Overweight Traffic Operations

Abstract

AbstractMechanistic-Empirical (ME) design and analysis of pavement structures are highly sensitive to the traffic data inputs. Hence, proper characterization of truck traffic is the key step for accurate assessment of performance and service life of pavements subjected to overweight (OW) traffic movements. Therefore, this study aimed to evaluate the impact of different traffic characterization methodologies on the predicted service life of pavements in overload corridors. To accomplish this objective, initially, the authors collected the site-specific traffic information by deploying Portable Weight-in-Motion (P-WIM) devices to ten representative pavement sections in Texas. Subsequently, non-destructive field tests such as Falling Weight Deflectometer (FWD) and Ground Penetrating Radar (GPR) were performed during summer and winter months for the back-calculation of the layer moduli in representative sites. Ultimately, different traffic data inputs, including the site-specific Axle Load Spectra (ALS), Equivalent Single Axle Load (ESAL) values, and software default values, as well as the pavement layer properties were incorporated into a series of ME analyses to estimate the service life of the pavements. The comparative analysis results indicated that the incorporation of ESAL and software default values in the analysis, instead of using site-specific ALS, substantially overestimated the service life of the pavements. Such deviation was more pronounced for pavement sections of Farm-to-Market roadways subjected to unprecedented OW traffic operations. Therefore, the traditional traffic characterization methodologies were not capable of representing the demanding loading conditions in the studied network. Further comparisons between the post-processed results and field distress records in this study showed that the most promising methodology to incorporate the traffic information into the service life analysis of pavements in overload corridors is the concept of the site-specific ALS.KeywordsMechanistic-Empirical (ME) analysisPavement service lifeAxle load spectraPortable Weight-in-MotionTexas overload corridorsOver-Weight (OW) trucks