Pavement Surface Roughness Research Articles

Dynamic Response Analysis of JPCP with Different Roughness Levels under Moving Axle Load Using a Numerical Methodology

In-service Portland cement concrete (PCC) pavements are subject to repeated dynamic loads from moving vehicles; thus, the actual stress generated in a PCC pavement may significantly differ from the static stress, which is normally used in the design and evaluation of pavement performance. Calculating the stress in PCC pavements under moving vehicle loads is of importance to assess their actual service condition, particularly for pavements with different surface roughness levels as the deteriorated roughness might cause large stress in PCC pavement subject to dynamic loads. In this paper, a method is proposed to compute the dynamic response in terms of loads and stresses generated in jointed plain concrete pavements (JPCPs) under a moving axle load, considering the effects of the pavement surface roughness, the vehicle parameters (including vehicle speeds and axle weights), and the pavement structure parameters (including thickness and elastic modulus of different layers and the existence of dowel bars). The dynamic axle load is firstly generated based on the quarter-car model, running through three successive slabs of which the surface roughness is determined by the power spectral density method, and the critical locations in slabs where the largest tensile stresses occur are identified. The combined effects of various pavement surface roughness levels, vehicle speeds, axle weights, and pavement structure parameters are evaluated in terms of the stress and the dynamic factor defined as the ratio of the tensile stress under dynamic load to the tensile stress under static load. For the roughness level D, the tensile stress can reach a maximum value of 3.13 MPa, and the dynamic factor can reach a maximum value of 2.46, which is much larger than the dynamic factor of 1.15 or 1.2 currently used in design guidebooks. Increasing the thicknesses of pavement slab or the subbase layer is an effective way to reduce the tensile stress in JPCP, while increasing the thickness of base layer is not effective. The results of this study can benefit future pavement design and pavement performance evaluation by providing the actual stress and the useful dynamic factor values for various conditions of field pavements. Moreover, preventive maintenance, particularly the improvement of pavement surface roughness, can be planned by referring to the results of this study, to avoid large tensile stress generated in JPCPs.

Development of an Unpiloted Aircraft System–Based Sensing Approach to Detect and Measure Pavement Frost Heaves

Abstract The combination of low temperatures, precipitation, and high-water table causes the formation of subsurface frost in pavements leading to the formation of frost heaves. This leads to significant damage to the structural integrity of the pavements and causes extensive surface roughness. Frost heaving is a common type of distress in cold climate regions, especially for road and airport infrastructures located in remote areas. Research discussed in this article focuses on determining the efficiency and accuracy of photogrammetry-based sensing systems to measure the extent of pavement frost heaves. The sensors are mounted on an unpiloted aircraft system (UAS) capable of providing measurements over large spatial domains in a single flight and are well suited for difficult-to-access regions. Experiments have been conducted on simulated heaves as well as actual cold climate pavement sections. The research described herein provides suitable UAS flight parameters for conducting frost heave measurements. Flight at an altitude of 50 m above the ground surface and a flight speed of 5 m/s with capturing images every 2 s resulted in more than 80 % front and side image overlap. The pavement surface profile has been constructed from extracted photogrammetry elevation data collected in three different seasons. Pavement surface roughness has been measured in terms of the international roughness index (IRI), and variation between measured IRI values has been evaluated during different seasons because of the formation of the frost heave distress. As it is expected, the IRI values increase as the cold season approaches. Moreover, the measured IRI values have been compared with the most recent available IRI data collected by an instrumented vehicle. The key outcomes of this work demonstrate that photogrammetry can reliably detect pavement frost heaves and provide high confidence in the future development of an automated system to measure pavement roughness that is attributable to frost heave distresses.

ЕФЕКТИВНІСТЬ ЗАСТОСУВАННЯ СИСТЕМ WIM НА АВТОМОБІЛЬНИХ ДОРОГАХ

Introduction. The introduction to the paper highlights the general role of the weight control of motor vehicles on roads by WiM – methods (Wegh-in-Motion) in the assurance of the traffic safety and in the transportation infrastructure preservation. Problem statement. The issues of the paper concern the problems of implementation of contemporary technologies of the High-Speed WiM (HS-WiM) where the conditions of the measurements of the loads from the vehicle generate high measurement error. Purpose. The main goal of the paper is to perform an analytical review of methods of the weight control of vehicles and of competitive aspects of existing WiM technologies and also the analysis of the practice of WiM application. Results. The analytical reviewing led to the following results: it was revealed that the basic principle of WiM systems operation consists in determining the dynamic wheel/axle loading of a vehicle transmitted to the pavement; data thus obtained shall be used to reveal the overloading. Modern WiM systems give possibilities to obtain data concerning axle number, axle spaces, vehicle length and speed, axle (or wheel) dynamic loading, number of equivalents of standard axle loading, and also data regarding the traffic flow characteristics; it was concluded that WiM systems can be divided into two main types: the systems operating at low speed of a vehicle (up to 15 km/h, LS WiM) and those operating at steady speed of the traffic flow (up to 130 km/h, or high speed, HS WiM). LS WiM ensure the accuracy of the measurement in a range from 3 % to 5 % and belong to the methods of weight control of motor vehicles approved by the legal metrology as well as the static weighing does. HS WiM control is more sensitive to the external factors due to the effect of a vehicle dynamic and thus cannot assure the above stated accuracy of measurements, moreover, cannot assure the appropriate accuracy for the satisfactory number of trucks. HS WiM systems are not approved by the legal metrology; factors affecting the accuracy of measurements in HS WiM systems were analyzed. It was revealed that the effect of a vehicle dynamic on the measurement error can be mitigated assuring the compliance of the road pavement surface condition with the standard requirements mainly with those concerning pavement surface roughness.

Investigation on the fractal characteristic of asphalt pavement texture roughness incorporating 3D reconstruction technology

<abstract> <p>The textural roughness of asphalt pavement surface is an important indicator to characterize pavement skid resistance. In this paper, multi-visual technology was applied to capture the surface image of asphalt pavement which was transformed into a visualized 3D point cloud model. Then, based on the principle of the digital elevation model (DEM), the disordered 3D point cloud is rasterized and projected into a 2D matrix which contains generalized point cloud elevation information. Meanwhile, the 2D matrix is transformed into grayscale to build the equivalent grayscale image. Furthermore, the fractal dimensions were calculated in terms of one-dimensional pavement section profile, two-dimensional grayscale, and equivalent grayscale to characterize the pavement roughness. The results showed that the fractal dimensions are positively correlated with the mean texture depth (MTD), and the fractal dimension of equivalent grayscale has the best correlation with MTD. It should be highlighted that the equivalent grayscale image is directly transformed by the reconstruction of the three-dimensional point cloud, and the grayscale value of each point can represent the elevation of different pavement surfaces. Therefore, the equivalent grayscale image can better reflect the real roughness of the pavement surface. Meanwhile, the proposed method in this paper can effectively reduce the influence of some factors (e.g., light and color, etc..) on the texture detection of the pavement surface.</p> </abstract>

Research on influencing factors of asphalt pavement International Roughness Index (IRI) based on ensemble learning

Abstract The International Roughness Index (IRI) is one of the most commonly used indicators to measure pavement surface smoothness. This paper uses the data obtained from the Specific Pavement Studies-3 (SPS-3) of the Long Term Pavement Performance (LTPP) program to study the influencing factors of the International Roughness Index of asphalt pavement. Pavement age, precipitation, freezing index, temperature, traffic volume, traffic load, and rutting depth are investigated to evaluate the effectiveness of four preventive maintenance treatments on asphalt pavement surface roughness. The pavement roughness model is established based on the XGBoost algorithm, with a training R2 of 0.96 and a testing R2 of 0.82. The results show that among the four preservation treatments, the IRI of thin overlay is the lowest. Annual Average Daily Traffic (AADT) is identified as the most significant factor for IRI evaluation, accounting for the most contribution to pavement surface roughness, followed by precipitation, rutting depth, temperature, etc.

Influence of Road Types on Transiting Test for Aerodynamic Coefficient Measurements Using Passive Wind Generated by a Moving Vehicle

A transiting test using vehicle-driving passive wind is a novel experimental technique to perform aerodynamic tests, proposed by the authors. However, this low-cost, short-cycle, and symmetrical test method can be influenced by many factors. In this paper, a comparative study on the influence of road types on a transiting test of aerodynamic coefficient measurements is presented. The tests were carried out on three different roads (expressway, viaduct highway, and tunnel highway); for each road type, structure models with and without end plates were investigated. For all the road types, measured turbulence intensity (around 4%) was similar to that of the wind tunnel test under the following conditions: 3 °C temperature, 42% humidity, 0.28 m/s natural wind speed, vehicle driving in a straight line with stable speed, and no traffic flow. All the tests were conducted under the above conditions. To deal with the interference components in the original data signals obtained from a viaduct highway and tunnel highway, a low-pass filter with a 1 Hz cutoff frequency was used. With wind attack angles changing, the tendency of the aerodynamic coefficients of the test model in the transiting test showed satisfactory consistency with that of the wind tunnel test; and the results exhibited fine repeatability. Regarding the drag coefficients, the test model with end plates was in good agreement with those from the wind tunnel test. Compared with the wind tunnel test, the results of expressway showed the best consistency, considering turbulence intensity, pavement surface roughness, and other factors. Thus, the transiting test in future research should be conducted on the expressway, with end plates installed on both ends of the structure model.

Study on hydrodynamic characteristics and influence factors of asphalt pavement runoff.

A hydrodynamic model is developed for rainfall-runoff on asphalt pavement using two-dimensional shallow water equations. A simple yet precise expression is presented to compute flow velocity in order to alleviate the problems associated with numerical instabilities due to small water depths of thin sheet flow. The developed model performed well against measured data and numerical results in two segments. Then, the model was applied to study the influence of highway horizontal alignment, drainage manner, rainfall pattern, surface roughness and geometric parameters on pavement runoff. The results demonstrate that: (i) the influence of highway horizontal alignment on pavement runoff is nonsignificant, while that of drainage manner and the pavement surface roughness is significant. Great differences are observed in flow depth under concentrated drainage and overflow drainage conditions, especially in the area beyond 6 m away from the highway center axis; (ii) remarkable differences in maximum flow depth and peak runoff are presented under uneven and even rainfall conditions, while no great differences are found under three uneven rainfall conditions (front type, center front type and back front type); (iii) the sensitivity of the geometric parameters to the maximum flow depth from strong to weak is cross slope, width, slope length, and longitudinal slope under overflow drainage condition; while that is width, slope length, longitudinal slope and cross slope under concentrated drainage condition.

On the Applicability of Laser Scanning for Evaluation of the Pavement Serviceability Parameters

Pavement performance is influenced by man factors such as climate and environmental conditions, traffic and operational conditions and type of pavement. These factors cause a pavement deterioration what leads to the restriction of the pavement serviceability or pavement efficiency. The pavement serviceability is the ability of the pavement to fulfil the service function represented by the actual values of variable parameters such as pavement surface roughness, surface evenness, pavement surface condition. The state of the pavement is assessed using different performance indicators when International Roughness Index (IRI) is most used. This approach allows to classify the state of the pavement in the pavement management system as a most used indexing, generalizes the pavement surface to the response of the testing car tire and the pavement. Laser scanning presented in this paper is able to bring the knowledge about the real pavement surface considering the accuracy of the method and equipment. Realized laser scanning proved the applicability of this method for the measurement of the pavement surface. Because of the complex knowledge of the pavement surface morphology, we can evaluate the pavement serviceability in terms of roughness, surface evenness or even pavement surface condition (rutting or cracks).

Enhanced Flexible Pavement Performance Using Treated Compared to Untreated Aggregate Bases: A Comparative Case Study in the Southern United States

One of the important aspects of highway design is aggregates. Aggregates strength and consistency has an effect on pavement structure’s overall performance. The consistency of the base material near the site of the construction doesn’t always match the requirements of pavement construction and carrying quality aggregate raises the cost of construction. Stabilizing agents such as asphalt cement, lime, fly ash were used to improve the strength of these materials in order to make greater use of locally available materials. Layer materials present in the pavements and the structure of them influence pavement performance. The compressive strain and the tensile strain in the layer of subgrade and asphalt layer respectively are influenced by the stiffness of the base layer. The important aspects causing rutting and fatigue cracking are compressive strain in the top region of the subgrade layer and tensile strain at the bottom of the asphalt layer, respectively. In this research study, field performance (cracking, rutting, and surface roughness) of pavement sections with untreated and treated bases were collated to assess the impact of the stabilizing agents. The treated sections performed well significantly compared to the untreated sections in terms of pavement surface roughness and fatigue cracking. The treated sections performed higher than the untreated sections in terms of the cumulative average values of all 3 distresses with fatigue cracking averaging 5 times lower than the untreated sections. The combined IRI and rutting of treated sections averaged about 1.5 times and 0.11 inches smaller, respectively than those of untreated sections.

Policy implications of standalone timing versus holistic timing of infrastructure interventions: Findings based on pavement surface roughness

Abstract Transportation agencies routinely make repair decisions in numerous contexts which include the timing of different repair treatments over an extended period. The timing policy may be characterized either by a standalone manner that maximizes the outcome or utility of individual treatments at a given time, or by a holistic manner that maximizes the utility of all treatments together within a given horizon period. This study begins with a hypothesis that the effect of the sum of treatment prescriptions may be different from the sum of the effect of individual treatment prescriptions. The paper discusses separate practical applications where each of these two situations is pertinent. The study is based on the use of surface roughness as the indicator of pavement performance, and therefore, the framework includes the development of treatment-specific treatment performance jump and performance loss models in terms of roughness. The framework also includes identification of the optimal roughness thresholds for each pavement treatment as a standalone activity, followed by a determination of the thresholds for each treatment from a holistic standpoint. The latter involves the establishment of an optimal repair schedule over the pavement life cycle and recording the resulting roughness thresholds at which each treatment is recommended for application within the optimal schedule. Then the paper presents a case study to demonstrate application of the framework, and to compare the optimal-schedule thresholds versus the stand-alone thresholds. The case study involved fourteen treatment types, two surface material types (rigid and flexible) and three road functional classes. The results suggest that in this context of highway management, the optimal triggers associated with individual standalone repair treatments are not necessarily the same (and yield inferior outcomes) compared to the application thresholds of those treatments when they are considered within an optimized life-cycle schedule. The results can provide guidance to agencies as they examine or update their current roughness thresholds for each standard treatment and their long-term condition-based or time-based repair schedules. The paper’s framework and results can also help agencies assess the consequences of deviations from a repair timing policy (delayed or hastened applications) due to lack of funds and other causes.

Can Machine Learning and PS-InSAR Reliably Stand in for Road Profilometric Surveys?

This paper proposes a methodology for correlating products derived by Synthetic Aperture Radar (SAR) measurements and laser profilometric road roughness surveys. The procedure stems from two previous studies, in which several Machine Learning Algorithms (MLAs) have been calibrated for predicting the average vertical displacement (in terms of mm/year) of road pavements as a result of exogenous phenomena occurrence, such as subsidence. Such algorithms are based on surveys performed with Persistent Scatterer Interferometric SAR (PS-InSAR) over an area of 964 km2 in the Tuscany Region, Central Italy. Starting from this basis, in this paper, we propose to integrate the information provided by these MLAs with 10 km of in situ profilometric measurements of the pavement surface roughness and relative calculation of the International Roughness Index (IRI). Accordingly, the aim is to appreciate whether and to what extent there is an association between displacements estimated by MLAs and IRI values. If a dependence exists, we may argue that road regularity is driven by exogenous phenomena and MLAs allow for the replacement of in situ surveys, saving considerable time and money. In this research framework, results reveal that there are several road sections that manifest a clear association among these two methods, while others denote that the relationship is weaker, and in situ activities cannot be bypassed to evaluate the real pavement conditions. We could wrap up that, in these stretches, the road regularity is driven by endogenous factors which MLAs did not integrate during their training. Once additional MLAs conditioned by endogenous factors have been developed (such as traffic flow, the structure of the pavement layers, and material characteristics), practitioners should be able to estimate the quality of pavement over extensive and complex road networks quickly, automatically, and with relatively low costs.

Evaluation of influence of pavement data on measurement of deflection on asphalt surfaced pavements utilizing traffic speed deflection device

Structural condition data is one of the critical data elements in pavement design and management for determining the needs of pavements rehabilitation. However, it is time-consuming and may raise safety concerns to use Falling Weight Deflectometer (FWD) for collecting pavement structure data at network-level. The traffic-speed deflection device seems to be a promising way to collect network-level structural capacity information in a safe and timely manner. To better understand the deflection collected from traffic-speed deflection devices, this paper focused on the influence of pavement data on deflection measurements. The pavement data in this study included pavement structure and surface condition data. The associations between deflection and pavement data was assessed by non-parametric rank correlation analysis. The pavement data elements that may influence deflection measurement were identified by random forest regression models. The relationship between deflection indices and surface condition indices were quantified by Tukey’s HSD test.Results indicated that D0 and SCI appeared to be more influenced by pavement type, surface roughness and distress than SCI of subgrade. IRI on the right wheel path tended to be more closely associated with SCI than other surface condition data. The change of surface condition indices appeared to be more sensitive to deflection indices on flexible pavements than on composite pavements.

Asphalt pavement modulus backcalculation using surface deflections under moving loads

AbstractThe measurement of pavement surface deflections under moving loads can be used for evaluation of pavement structural condition. The objective of this paper is to develop an innovative backcalculation method to calculate pavement layer moduli based on traffic speed deflectometer (TSD) measurements and analyze factors influencing backcalculation results. The backcalculation method is based on 2.5D finite element method (FEM) and constrained extended Kalman filter (CEKF). Field measurements at different pavement sections were used to verify the accuracy of backcalculation results. Parametric analysis was conducted to evaluate the influences of traffic loading and pavement structure variations in the field. It was found that the backcalculation results were considerably affected by the variation of asphalt layer thickness and dynamic loading due to pavement surface roughness. A heavy truck passing the adjacent lane during TSD testing could also cause variation of backcalculation results.

Flexible Pavement Response Analysis under Dynamic Loading at Different Vehicle Speeds and Pavement Surface Roughness Conditions

AbstractPavement responses are affected by the magnitude and frequency of dynamic loads generated by vehicles, which are significantly dependent on axle configuration, pavement surface roughness, a...

Development of a crowdsourcing-based system for computing the international roughness index

ABSTRACT Pavement roughness is one of the essential parameters of pavement quality affecting ride quality, driving safety, and fuel consumption. The International Roughness Index has been widely deployed to evaluate pavement surface roughness. A vibration-based system is developed by using a low-cost three-axis Micro-Electro-Mechanical Systems accelerometer and a Global Positioning System sensor, which are connected to an Arduino board and embedded in a vehicle to monitor the road condition. The pavement profile is obtained by double integration of Z-axis acceleration data, and then the International Roughness Index is calculated via the Process Valves & Automation Systems Software using the obtained profile. The calculated International Roughness Index is correlated with ground truth data captured by a Road Surface Profiler with the coefficient of determination of 0.82 and an average error of 15%. The results demonstrate that the developed system can calculate the International Roughness Index with adequate accuracy at the network level. Besides, due to the low system cost and ease of use, it can be widely applied by road users to monitor pavement roughness as a crowdsourcing-based data collection system.

Effect of Pavement Roughness and Transverse Slope on the Magnitude of Wheel Loads

Pavement distresses are assumed to occur uniformly along the left wheel path and right wheel path of the vehicles within a lane. However, there can be a significant difference in the magnitude of a particular distress between each of wheel paths due to transverse slope. Transverse slope significantly affects the magnitude of wheel load that is being transmitted to the top of pavement surface in each of the wheel paths. The magnitude of wheel load would be higher on the outer wheel path with reference to the median for a dual carriageway resulting in higher distresses. In a similar manner, rough pavement deteriorates at a much faster rate compared to smooth pavement as the magnitude of dynamic loads increases with increase in pavement surface roughness. Such effects are not taken into account in stress analysis and subsequent distress quantification. The focus of the current study is to quantify the magnitude of excess wheel loads due to the combined effects of pavement roughness and transverse slope. A fully loaded two-axle truck movement using TruckMaker software was simulated on a pavement surface by varying the pavement roughness and the transverse slope. Taking into account the initial roughness over a newly constructed pavement, the magnitude of axle load increased by 9% compared to the standard axle load. Further, the increase in magnitude of wheel load acting on the outer wheel path varied between 3.32 and 4.85% compared to the inner wheel path for a given pavement roughness profile by considering the standard range of transverse slopes.

Treated versus Untreated Aggregate Bases for Flexible Pavements: Nationwide Comparative Case Study

Aggregates constitute a major part of pavement construction. The strength, durability, and quality of the aggregate affects the overall performance of the pavement structure. Materials sourced near a construction site do not always meet the strength required for pavement construction, however, and haulage of aggregates of the required quality is often costly. For better use of locally available materials, stabilizing agents such as lime, cement, asphalt cement, and fly ash are often used to enhance the strength of the local aggregates. Pavement performance is influenced by both the structure itself and the layer materials present in it. The stiffness of the base layer, for instance, influences the tensile strain in the asphalt layer and compressive strains in the subgrade soil. The tensile strains at the bottom of the asphalt layer and compressive strains in the top zone of the subgrade soils are the main response components affecting fatigue cracking and rutting, respectively. In this study, field performance [rutting, cracking, and roughness measured in relation to the International Roughness Index (IRI)] of pavement sections with treated and untreated base layers were compared to determine the effects of stabilizing agents. In relation to fatigue cracking and pavement surface roughness, the treated sections outperformed the untreated sections. The average values of all three distresses showed better performance for the treated base layer sections with fatigue cracking averaging 2.2 times lower than the untreated sections. The combined rutting and IRI of the treated base layer sections averaged about 0.10 in. and 1.4 times lower than those of the untreated base layer sections, respectively.

Comparison of pavement surface roughness characteristics of different wearing courses evaluated using 3D scanning and pendulum

Road pavement roughness, in terms of skid resistance, can be described from a geometrical point of view as a texture or from a physical point of view as friction between a tire and a road surface. The paper deals with the comparison of asphalt and concrete pavement surface on selected newly built sections of the D1 motorway near the Ovčiarsko tunnel. Texture measurements were performed with a Static Road Scanner (SRS) capable of recording surface irregularities up to the microtexture level (2.49 µm resolution). A pendulum was used to determine the friction. Subsequently, the texture was evaluated using individual amplitude and wavelength characteristics and the friction was evaluated using the PTV parameter. Finally, correlations were searched between the roughness characteristics of asphalt concrete and cement concrete pavements, but also between texture and friction characteristics.

Methodologies for assessing the longitudinal roughness of airport taxiways and runways

As a significant indicator of the condition of airport surfaces, the longitudinal roughness significantly affects the comfort and safety of passengers and crew members when navigating the airplanes on the airport taxiways and runways, which is why the location of uneven zones and their prompt rehabilitation is one of main tasks in managing the airport infrastructure. Several different methodologies are available to assess the pavement surface roughness. Some of them, such as the International Roughness Index (IRI), have been taken from road practices. Boing has developed a methodology that takes into account differences in the design of aircraft and road vehicles and this methodology is specified within the ICAO (International Civil Aviation Organization) standard. In addition, various softwares are being developed which, using mathematical models, simulate aircraft movement along the measured profile, and thus determine the parameters related to longitudinal roughness of the surface. This paper presents the methods and their application on a concrete example of an airport runway pavement.

Use of grid reinforcement in HMA overlays – A Texas field case study of highway US 59 in Atlanta District

Abstract One of the common methods to mitigate reflective cracking, in existing cracked pavements, is the use of interlayer grid reinforcements in hot-mix asphalt (HMA) overlay construction during maintenance and/or rehabilitation projects. As a means of sharing the practical experience, lessons learned, and demonstrating the performance benefits of using interlayer grid-reinforcements, this paper presents a field case study where different types of grid reinforcements (namely geosynthetic paving mats) were used in HMA overlay construction to mitigate reflective cracking and thereafter, field performance was monitored and evaluated periodically. Two HMA overlay test sections (denoted as Sec13 and Sec14), reinforced with different grid materials (i.e., geosynthetic paving mats) were constructed in 2011 over an existing cracked HMA pavement (with transverse cracks) on an in-service highway US 59 in the Atlanta District of Texas. Field performance was subsequently monitored/evaluated for a period of over seven years against an adjacent Control section (Sec01), without grid reinforcement, on the same US 59 highway. Under the same pavement structure, traffic loading, and climatic conditions, various performance indices were evaluated semi-annually including reflective cracking, rutting, longitudinal surface profiles, and interlayer bonding. While the rutting performance was indifferent on all the three test sections after 7 years of service, 17% of reflective cracking was measured on the Control section versus 4% on the grid-reinforced test sections – demonstrating that the use of grid reinforcement (namely geosynthetic paving mats) has been effective in mitigating reflective cracking from the existing cracked HMA pavement. Similarly, while coring indicated satisfactory interlayer bonding conditions on all the three test sections, the rate of pavement surface roughness deterioration was also hardly different on all the three test sections – albeit that the Control section (Sec01) exhibited superiority in terms of the profile indices (smoothness/serviceability) than the grid-reinforced test sections (Sec13 and Sec14).