No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Simulation of autonomous truck for minimizing asphalt pavement distresses
Abstract
The improvement of the pavement performance by different means is essential for the smooth movement of autonomous trucks (ATs). This study focuses on minimising the pavement distress by controlling vehicular loading distribution pattern (wander), traffic distribution on lanes (lane sharing) of a road, and limiting the running duration of AT to low-temperature time only. Mechanistic-Empirical Pavement Design Software, AASHTOWare, was incorporated in this research to analyze and then minimise the generation of asphalt pavement distress from autonomous truck loading. Different loading distribution patterns and traffic distribution of autonomous trucks were devised in AASHTOWare using the load equivalency factor (LEF) and lane distribution factors. Using multilayer elastic theory, LEFs were calculated for fatigue cracking and rutting separately. The acquired performances clearly showed significant improvement in pavement distress for a small increase of standard deviation of wheel wander and uniform distribution of traffic loading and for equally distributed ATs on the road lanes. In addition, an attempt has been made to optimise pavement distress in putting all ATs in a low-temperature duration of a day. Placing all ATs in a certain period of a day is beneficial for reducing asphalt pavement distresses and can bring a fruitful solution to prevent the early deterioration of the pavements.
... Automated vehicles' deployment may affect the roads' pavement performance and cause a drastic change in pavement analysis and design (Chen et al. 2016, Noorvand and Underwood 2017, Chen et al. 2019, Zhou et al. 2019, Gungor and Al-Qadi 2020a, 2020b, Rana and Hossain 2021, Yeganeh et al. 2021a, 2021b. One of the most significant aspects of AVs', which might influence pavement loading, is the AVs' different possible lateral wandering patterns. ...
... In recent years, there has been an increasing amount of literature on studying the effects of using different lane distribution policies for the interactions between AVs and HDVs on different aspects of the transportation system operation and design (Liu and Song 2019, Mohajerpoor and Ramezani 2019, Amirgholy et al. 2020, Razmi Rad et al. 2020. However, little attention has been drawn to the effects of lane distribution of AVs and HDVs on pavement performance (Noorvand and Underwood 2017, Chen et al. 2019, Rana and Hossain 2021. In this regard, Noorvand and Underwood (2017) investigated the design thickness and initial construction costs for both segregated and integrated scenarios. ...
... They demonstrated that when the AVs' penetration rate is more than 50%, applying the two-section uniform-wander mode for AVs delays the maintenance year by 2.3 years. Rana and Hossain (2021) simulated the autonomous trucks' pavement performance through the Mechanistic-Empirical Pavement Design Software, AASHTOWare, to minimise the pavement distresses by controlling the wander distribution and lane sharing scenarios. They simulated both separated and integrated scenarios, and they classified the integrated scenarios into equally distributed and disproportionately distributed cases. ...
The deployment of automated vehicles (AVs) with the gradual market penetration rate increase and different potential lateral movement patterns combined with the lane width effect would lead to different load distribution scenarios, impacting the pavement performance. This study compares pavement rutting damages induced by different load distribution scenarios by setting out different penetration rates (i.e. 0, 20, 40, 60, 80, and 100%), wander modes (i.e. zero-, normal-, uniform-time-, and uniform-frequency-wander), and lane widths (i.e. 3, 3.25, and 3.5 m). A finite element model of a full-depth flexible pavement was developed using ABAQUS software to evaluate the pavement rutting. The results showed that the significance level of differences between rutting damages induced by different wander modes and lane widths is substantially influenced by the AVs’ penetration rate. For instance, in the higher penetration rates, the differences between the rutting performance of different wander modes are more significant than in the lower penetration rates. Furthermore, the lane width effect becomes more significant in the segregated scenario than in the integrated scenarios in normal- and uniform-wander modes. Accordingly, AVs’ penetration rate is a decisive factor in the practical decision-making process in the wander mode determination and lane width design for AVs.
... To address this issue, recent research studies, mainly based on numerical simulation, have analysed the impact on pavement performance of different variables representative of truck platoon configurations: distribution of the lateral deviation (wandering) (Chen et al. 2019(Chen et al. , 2020Gungor et al. 2020;Al-Qadi 2020b, 2020a;Marsac et al. 2020;H. Noorvand, Karnati, and Underwood 2017;Rana and Hossain 2021;Song, Chen, and Ma 2021;Zhou et al. 2019), inter-vehicle distances (Gungor et al. 2017(Gungor et al. , 2020Gungor and Al-Qadi 2020a) and traffic distribution scenarios (Hoque et al. 2021;Rana and Hossain 2021). Their analysis confirms the need to control wandering Al-Qadi 2020a, 2020b;Rana and Hossain 2021;Zhou et al. 2019), inter-vehicle distances (Gungor et al. 2020), and to limit the circulation of platoons to specific lanes or during particular periods (Hoque et al. 2021;Rana and Hossain 2021) to preserve the fatigue performance, self-healing capacities of the pavement, and maintenance costs (Gungor et al. 2020;Gungor and Al-Qadi 2020a). ...
... To address this issue, recent research studies, mainly based on numerical simulation, have analysed the impact on pavement performance of different variables representative of truck platoon configurations: distribution of the lateral deviation (wandering) (Chen et al. 2019(Chen et al. , 2020Gungor et al. 2020;Al-Qadi 2020b, 2020a;Marsac et al. 2020;H. Noorvand, Karnati, and Underwood 2017;Rana and Hossain 2021;Song, Chen, and Ma 2021;Zhou et al. 2019), inter-vehicle distances (Gungor et al. 2017(Gungor et al. , 2020Gungor and Al-Qadi 2020a) and traffic distribution scenarios (Hoque et al. 2021;Rana and Hossain 2021). Their analysis confirms the need to control wandering Al-Qadi 2020a, 2020b;Rana and Hossain 2021;Zhou et al. 2019), inter-vehicle distances (Gungor et al. 2020), and to limit the circulation of platoons to specific lanes or during particular periods (Hoque et al. 2021;Rana and Hossain 2021) to preserve the fatigue performance, self-healing capacities of the pavement, and maintenance costs (Gungor et al. 2020;Gungor and Al-Qadi 2020a). ...
... Noorvand, Karnati, and Underwood 2017;Rana and Hossain 2021;Song, Chen, and Ma 2021;Zhou et al. 2019), inter-vehicle distances (Gungor et al. 2017(Gungor et al. , 2020Gungor and Al-Qadi 2020a) and traffic distribution scenarios (Hoque et al. 2021;Rana and Hossain 2021). Their analysis confirms the need to control wandering Al-Qadi 2020a, 2020b;Rana and Hossain 2021;Zhou et al. 2019), inter-vehicle distances (Gungor et al. 2020), and to limit the circulation of platoons to specific lanes or during particular periods (Hoque et al. 2021;Rana and Hossain 2021) to preserve the fatigue performance, self-healing capacities of the pavement, and maintenance costs (Gungor et al. 2020;Gungor and Al-Qadi 2020a). ...
Truck platooning is a recent solution proposed to optimise road transportation. Platooning can help improve transport efficiency and road safety, reduce traffic congestion, fuel consumption and greenhouse gases emissions. Considering that truck platoon configurations are new, studying their impact on pavement response and damage is crucial. In this context, this study presents the results obtained in a full-scale experiment designed to evaluate the structural responses of a test track subjected to the pass of trucks under two configurations: individual and platoon. The pavement was instrumented to measure the transverse and longitudinal strains at the bottom of the asphalt layers of the pavement structure. Strains were measured under two test configurations, individual trucks and platoons, for four vehicle speeds: 40 , 60 , 70 , and 80 km/h. In order to consider the weather influence, two test campaigns were performed, one during the winter and the other during the summer. The study's main conclusion is that by managing inter-truck distances, truck speeds, lateral deviation (wandering), time, and periods of circulation, it is possible to minimise the impact of platooning trucks on the pavement's structure responses.
... However, platooning trucks introduce new traffic multi-load configurations with the following two characteristics: (1) reduced deviation of the lateral position of the vehicles forming the platoon and therefore load channelization (1,11,12,(18)(19)(20)(21)(22)(23)(24) and (2) reduced inter-truck distances between the trucks in the platoon, which may hinder the self-healing capacity of asphalt concrete materials (11,12,22). In this sense, a truck platoon deployment without precaution could accelerate pavement damage in the form of lower fatigue cracking/ permanent deformation (1,11,12,20,21,23,24) and lead to earlier rehabilitation/maintenance treatments (18,23). ...
... However, platooning trucks introduce new traffic multi-load configurations with the following two characteristics: (1) reduced deviation of the lateral position of the vehicles forming the platoon and therefore load channelization (1,11,12,(18)(19)(20)(21)(22)(23)(24) and (2) reduced inter-truck distances between the trucks in the platoon, which may hinder the self-healing capacity of asphalt concrete materials (11,12,22). In this sense, a truck platoon deployment without precaution could accelerate pavement damage in the form of lower fatigue cracking/ permanent deformation (1,11,12,20,21,23,24) and lead to earlier rehabilitation/maintenance treatments (18,23). ...
... However, platooning trucks introduce new traffic multi-load configurations with the following two characteristics: (1) reduced deviation of the lateral position of the vehicles forming the platoon and therefore load channelization (1,11,12,(18)(19)(20)(21)(22)(23)(24) and (2) reduced inter-truck distances between the trucks in the platoon, which may hinder the self-healing capacity of asphalt concrete materials (11,12,22). In this sense, a truck platoon deployment without precaution could accelerate pavement damage in the form of lower fatigue cracking/ permanent deformation (1,11,12,20,21,23,24) and lead to earlier rehabilitation/maintenance treatments (18,23). ...
Truck platooning for the transportation of loads is a strategy recently proposed by the automotive sector to cope with traffic congestion, fuel consumption, and operational costs. This new way of configuring trucks changes the typical pressures pavements
structures experience. For this reason, the research efforts of the pavement sector should be aligned with the automotive sector to propose road-friendly platoon configurations. This is one of the objectives of the European project ENSEMBLE. ENSEMBLE, as indicated by its acronym, works on ENabling SafE Multi-Brand pLatooning for Europe. In this context, the present study presents a real scale test done in the Applus IDIADA facilities to evaluate the fatigue behavior of a pavement structure subjected to individual and platoon truck configurations. The effects of parameters such as traffic distribution
through the year and by time of day, percentage of platoons, truck loads, number of trucks in platoon configuration, lateral wandering, and inter-truck distances were evaluated. The study’s findings revealed that the reduced rest times between trucks in the platoon configuration reduce the recovery time of the asphalt layers, increasing the fatigue damage to the pavement at high temperature conditions. This underlines the need for further research to allow the proper implementation of truck platoons. For example, research is needed to define strategies to make truck platoon configurations more pavement friendly and analyze the costs associated with the changes in the required road maintenance/rehabilitation treatments, among others.
... (2) traffic channelization, by the reduction of the lateral deviation of the trucks (Chen et al. 2019, 2020, Gungor et al. 2020, Gungor & Al-Qadi 2020b, 2020a, Marsac et al. 2020, Noorvand et al. 2017, Rana & Hossain 2021, Song et al. 2021, Zhou et al. 2019, and ...
... Other studies (Rana & Hossain 2021), also based on mechanistic-empirical analysis of pavements, found that increasing the wander uniformly and assigning mainly the traffic to low-temperature periods of the day can reduce pavement distress projections due to fatigue and rutting. ...
Partially/fully self-driven trucks in platoon configurations promise to increase transport efficiency, reduce fuel consumption/gas emissions and improve road safety through the use of connectivity technologies and automated driving support systems. However, truck platooning means the introduction of new types of loads on pavements which are characterised by: multiple loads, generated by the multi-axle configurations of the different trucks forming the platoon, traffic channelisation by the reduction of the lateral deviation of the trucks, and reduced inter-truck time gaps, which may reduce the self-recovery capacity of asphalt concrete materials, reducing the pavement service life. In this context, this study presents a parametric analysis carried out to evaluate a pavement structure subjected to several platoon truck configurations. The results of the study indicated that to keep the same pavement structural response as for individual trucks, it is possible to act on the following parameters in the platoon configuration: traffic distribution along the year and along the time of the day (avoiding traffic at higher temperatures), percentage of platoon penetration in the daily and annual traffic, level of loading of the trucks, number of trucks in platoon configuration, wandering, and inter-truck time-gaps/distances.
... The LEFs for maximum fatigue and AC rutting are presented. The presented LEFs are compatible with the studies by Noorvand et al. (2017) and Rana and Hossain (2022b). These LEFs are used to adjust truck traffic volume for incorporating AVs and uniform loading distribution in MEPDG. ...
... Decentralised optimisation: optimising the lateral position of each truck in a single platoon. (Rana & Hossain, 2021) Country: Canada. ...
https://platooningensemble.eu/storage/uploads/documents/2023/03/13/ENSEMBLE-D4.1-Assessment-of-platoon-axle-loads-on-road-infrastructure_FINAL.pdf
... The software used in this study is AASHTOWare Pavement ME Design (mechanistic-empirical) to analyze and minimize the generation of distress in asphalt pavement from autonomous truck loading. This is achieved by using the multilayer elastic theory, which is applied by using the load equivalency factor for various patterns of load and traffic distributions [21][22][23]. ...
Autonomous vehicles and truck platooning have become the future in the transportation
field. This new strategy has many benefits because it lowers fuel consumption and CO2 emissions,
improves safety, optimizes transport by using roads more effectively, and reduces traffic congestion.
In this research, the effect of the controlled positioning of autonomous and non-autonomous truck
loadings on the long-term performance of pavement was estimated using different variables such
as climate, uniform wandering values of distance between trucks, and percentage of autonomous
trucks by using MEPDG/AASHTOWare Pavement ME Design software. This was achieved by first
computing the strain and stress of the different loading combinations, resulting in the computation
of the failures in the pavement infrastructure and the pavement thickness needed to support each
combination. The second part of the research consisted of designing a platoon strategy that was
developed for a series of autonomous and connected trucks such that the lateral position of the trucks
and the spacing between them could be explicitly optimized to minimize flexible pavement damage.
The findings revealed that a small percentage of autonomous trucks can be beneficial to pavement
life and that truck platooning following a well-studied skeleton can open a whole new world of
pavement design. This can be revolutionary in changing roads around the world to improve traffic
and infrastructure.
... The study found a significantly greater total rutting induced by the narrower lane for AVs. In addition to lateral distributions of ATs, Rana and Hossain (2022) further studied the temperature effects and suggested that AT should be scheduled in a low-temperature time span of all the days is beneficial for minimising pavement distress. Chen et al. (2019) evaluated the various impacts of different ATs' lateral control modes on flexible pavements. ...
... In these conditions, trucks in platoon configuration lead to new loading conditions for pavement structures, characterised by (1) multiple loads passing in a reduced time over the pavement, (2) reduced lateral wandering of the vehicles forming the platoon and therefore load channelization (Chen et al., 2019(Chen et al., , 2020Gungor et al., 2020;Gungor & Al-Qadi, 2020b, 2020aMarsac et al., 2020;Noorvand et al., 2017b;Rana & Hossain, 2021;Song et al., 2021;Zhou et al., 2019) and (3) reduced inter-truck distances between the trucks in the platoon, which may hinder the self-healing capacity of asphalt concrete materials (Gungor et al., 2017(Gungor et al., , 2020Gungor & Al-Qadi, 2020b, 2020a. ...
This paper presents part of the studies developed in the European project ENSEMBLE. (ENabling SafE Multi-Brand pLatooning for Europe). The first part of the paper describes the validation of a numerical model based on comparisons with experimental results obtained from a test section subjected to the pass of 3 human-driven trucks simulating a platoon configuration. The numerical model is then used to predict the maximum and accumulated strains produced by the passage of each truck on the same test section at two different temperatures when the following platoon parameters are varied: (1) inter-truck time gap, (2) truck speed and (3) lateral deviation (wandering). The results confirm that the proper control of these parameters can help to keep the same level of fatigue damage as with trucks in individual configurations. In this way, the environmental, social and economic benefits of platooning can be attained without compromising the existing pavement structures.
... Few researchers have recently developed strategies to optimize the additional pavement distresses accumulated for the movement of AT. Researchers mainly focused on controlling the wheel loading distribution and vehicle positioning on the pavement lane explicitly [102,115,116]. Noorvand et al. deviation for wheel loading distribution of AT along the lane width is three times narrower than human-driven vehicles. ...
The continuous integration of advanced driver-assist systems (ADAS) into connected and autonomous vehicles (CAV) is accelerating the transition of human-driven vehicles to a fully driverless option. The most available ADASs in current running vehicles with their functions, level of autonomy, and present scenario of CAV deployment are critically reviewed and summarized in this paper. The expected advantages with the probable and observed uncertainties of the CAV deployment are also presented. The technological accomplishments (advanced digital infrastructures along with other technologies) are incorporating rapid improvement in vehicle automation. This paper reviews the engagement of technologies in the functioning of automated vehicles and their implementation challenges. Physical infrastructures facilitate the features of automation and connectivity in moving on the roads. Various roadside infrastructures with the issues in assisting the CAV for path tracking are summarized in this paper. The reduction of lane width due to lane-keeping ADAS and replacement of human drivers (i.e., eye) by machine impacts the various geometric elements of highways. The reduced lane width and truck platooning from the integration of cooperative adaptive cruise control affect the structural performance of the pavements significantly. This paper addresses the effects of connected and automated driving on geometric elements and the structural performance of highways. In addition, various techniques to minimize the additional distresses of connected and automated driving are also explained in this paper.
... Resilient modulus is the critical variable in asphalt pavement design, increases at low temperatures (Ghao et al., 2019;Zhao et al., 2020). Rana and Hossain (2021) simulated autonomous traffic movement at low-temperature period of the day and found relatively lower pavement distresses. An attempt has been made in this study to minimise the effects of autonomous vehicles by scheduling vehicle movement in the period of low-temperature duration of a day. ...
This study aims to evaluate the effect of the autonomous trucks on distresses of asphalt concrete (AC) pavement and determine the influence of the induced distresses on traffic safety factors in wet weather conditions. Two scenarios-the baseline and autonomous scenarios were simulated by the standard deviation of normally distributed truck traffic loading. Compared to baseline, all autonomous simulations have a negative impact on AC rutting, and corresponding skid resistance and hydroplaning potential. A graphical relationship has been proposed to obtain a design threshold value for hydroplaning speed of a standard tire, water film depth, and autonomous truck speed. This was proposed to remove the contradiction between hydroplaning speed and accumulated rutting with increasing truck speed. The placement of all autonomous trucks in a certain low-temperature period of a day was found to be beneficial for reducing asphalt pavement rutting and might bring improvement in highway safety issues. ARTICLE HISTORY
This chapter deals with the materials and design aspects of asphalt pavements. In the first part of the chapter, some of the upcoming technologies arising out of recent research, since the last decade or so, are highlighted. The immediate research challenges are also identified. In the second part, possible future directions are discussed briefly.
Recent research studies have provided useful insights into the impact of the Autonomous Trucks ’s (AT) wheel wander on pavement performance. However, only a single road structure, asphalt mix stiffness and asphalt mix thickness are considered in these studies. With these in mind, the present study aims to extend previous limited research results and present a more comprehensive insight into the relationship between AT wandering and the performance of flexible pavement asphalt layers with different thicknesses and asphalt stiffness. For the investigation, a pavement analysis was done on flexible pavement cross-sections with variations in the base and subgrade mechanical characteristics. In addition, for each cross-section the HMA thickness and stiffness varied. The ATs’ lateral position was modelled by four distinct distribution patterns: the zero, normal, uniform and Laplace . A static and dynamic pavement analysis was performed with the Mechanistic Empirical Pavement Design Guide (MEPDG) to determine pavement performance in terms of fatigue cracking and rutting of the asphalt layer. Analysis results showed that the zero lateral distribution of ATs hurts pavement performance. On the other hand, when ATs wheel paths are distributed uniformly in the lateral direction within the lane, the accumulated damage is significantly reduced.
The lateral position of truck loading is a random phenomenon for human-driven trucks because they do not follow a straight path as they travel. Therefore, this variable has been called as wheel wandering in the pavement design community and has been considered in an implicit way. However, with the introduction of autonomous and connect trucks (ACTs), this variable is expected to be controllable using the embedded auto-pilot and communication technologies. Hence, it should be considered explicitly to accurately simulate the impact of ACTs on pavement damage accumulation. This study presents a framework that improves any analytical pavement damage accumulation approach to take a lateral position of loading as an explicit input. In this paper, the developed framework was applied on the state-of-the-practice pavement design approach, Mechanistic-Empirical Pavement Design Guideline (MEPDG). MEPDG's damage accumulation equations (i.e. rutting and fatigue cracking) were reinforced with curve fitting and function approximation techniques for explicit consideration of the lateral position. A simple numerical example was presented in the paper to demonstrate the effects of positioning wheel loads on accumulated damage.
This study was aimed to determine the extent of association between network-level pavement condition and seasonal and annual weather variations. Pavement condition data recorded in the Texas Department of Transportation’s Pavement Management Information System (PMIS) database between 2000 and 2008 was highlighted. Meteorological data collected at different districts across the whole state were used in the explanatory variables. Dynamic panel data analysis was used in the deterioration models to quantify the effects of temperature and precipitation variations on pavement conditions. Based on the statistical implication from the model estimation results, significant correlations were identified between pavement conditions, the average monthly rainfall, and the average monthly temperature recorded 1 to 23 months prior to pavement condition inspection.
There is much research conducted on the vehicle technologies required for operation of autonomous vehicles (AV) on public roads, as well as analysis of the interaction between AV and the road environment. However, limited research exists on the impact of AV on road pavement structures. The research includes issues such as the effect of more channelized traffic loading, shorter inter-vehicle following distances and potential higher traffic volumes of more uniform vehicle types and loads. This paper discusses the application of existing and generation of new, relevant accelerated pavement testing (APT) data in understanding the effects of AV on pavement infrastructure. The paper presents development of provisional guidelines for the use and application of APT data to ensure that road pavement structures cope with anticipated increase in AV use. It is concludes that the use of AV fleets on existing road pavement infrastructure may lead to different behaviors and responses than what became the norm under non-autonomous vehicle fleets; appropriate analysis of existing APT data will contribute to the improved understanding of these expected changes in behaviors and responses; appropriate planning of AV operations-focused APT is possible with existing technology to contribute to the provision of economic and durable road pavement infrastructure in future.
With ongoing technological improvements and research in the field of autonomous vehicles, it is becoming evident that the technology has the potential to substantially affect the transportation sector. Although the potential benefits with respect to productivity increases, cost decreases, and safety are evident, the potential for these vehicles to negatively or positively affect the transportation infrastructure is unclear. In this study, the influence of truck loadings positioning on the long-term performance of transportation infrastructure was estimated by carrying out performance simulations of pavement structures. Scenarios considering both full and partial use by autonomous trucks were considered. In all cases, performance was estimated with respect to rutting, fatigue cracking, and overall pavement smoothness, and the results were compiled in terms of reduced pavement thickness. It was found that if controlled appropriately, autonomous trucks could be highly beneficial for the pavement infrastructure design, and they would be most effective when they represented more than 50% of the total truck traffic. It was also found that in the absence of appropriate control, specifically by repeatedly positioning trucks in the same location, the amount of damage could be highly detrimental, and noticeable influences may occur at autonomous truck volumes as low as 10%.
This work focuses on the development of an algorithm for the prediction of a transformer core deformation, using a magneto-mechanical approach. An imposed magnetic flux method coupled with finite element modeling is employed for the magnetic resolution. The constitutive law of the material uses a simplified multi-scale model describing both magnetic and magnetostrictive anisotropies. Magnetostriction is introduced as an input free strain of a mechanical problem to get the deformation and displacement fields. The numerical process is applied to compare the deformations of a given magnetic circuit made of Grain Oriented and Non-Oriented FeSi, and an improvement of geometry leads to better performances.
Pavement design is evolving from the experimental American Association of State Highway and Transportation (AASHTO) Pavement Design Guide to the Mechanistic-Empirical Pavement Design Guide (MEPDG) (AASHTOWare Pavement ME Design). In the latter method, the predicted mechanistic responses of the pavement structure (strains and deflections) are empirically correlated to field-observed distresses. Therefore, mechanistic response data from instrumented, full-scale test road facilities are essential for the validation and further development of the MEPDG models. The University of Alberta’s Integrated Road Research Facility (IRRF) includes an extensively instrumented test road, with a variety of asphalt strain gauges and earth pressure cells in the unbound layers to capture the flexible pavements’ mechanistic responses to dynamic traffic loading. This paper focuses on investigating the effect of operational speed and lateral wheel wander on longitudinal tensile and vertical compressive strain measurements at the bottom of the Hot Mix Asphalt (HMA) layer (εl and εc) and compressive stress measurements in the granular base course (GBC) and subgrade (σc). During a field experiment at the IRRF, a test truck with predetermined axle loads was driven at four different speeds and two symmetric lateral offsets with respect to the outer wheelpath. Longer load durations (lower loading frequency) were observed
at lower truck speeds in the HMA and unbound layers. Also, the magnitude of εl
and εc increased when speed decreased. Similarly, higher vehicle speed resulted in less σc within the GBC and subgrade. Sensitivity of fatigue cracking and rutting models in the MEPDG to operational speed was investigated in a sensitivity analysis. To do so, an MEPDG-simulation of the test section was developed using the backcalculated moduli of each layer obtained from Falling Weight Deflectometer (FWD) test performed at the IRRF. The rate of both alligator cracking and rutting was found to decrease at operational speed of 60 km/hr. It was also found that the MEPDG underestimates the effect of speed on the predicted fatigue cracking and rutting.
A mechanistic empirical (M–E) approach has been developed and used to calculate the degradation behaviour of an arterial road in Southern Sweden. The results were then compared with measurements from the Swedish long-term pavement performance (LTPP) database. The arterial road had reached the critical 15 mm rut after 18 years in operation. The M-E approach used was a two-step procedure where the response of the structure was calculated mechanistically and thereafter the performance predicted empirically based on scaling of laboratory test results. Extensive laboratory testing was carried out on samples taken from the test road. Traffic counting and Bridge Weigh-in-Motion data were used to determine the amount of traffic loading, and data from weather stations were used to take into account the temperature dependency of the asphalt bound layers. The analysis shows that the rutting development can be simulated adequately although the calculations show a slower rate than the measurements towards the end of the simulated period. The discrepancy in the rate of rutting between the measurements and the observations that was observed after about 9 years of operation might be due to the fact that no ageing, seasonal variation including the spring thaw period or changes in structural integrity of the pavement structure were incorporated in the numerical analysis but surely observed in reality.
Accelerated pavement tests (APT) using heavy vehicle simulator (HVS) are regularly used to evaluate rutting performance of different asphalt mixtures. These tests are typically conducted at elevated temperatures and with channellized traffic. However, actual highway traffic always has certain amount of wander. It is therefore important to understand the effect of traffic wander on rutting performance of an asphalt concrete (AC) mixture in HVS tests. This paper presents finite element simulation of progressive rutting development in a HVS test on a flexible pavement. A constitutive model based on bounding surface plasticity is developed to describe the plastic flow of AC material. The model parameters are identified using RSST-CH (repeated simple shear test at constant height) test data. The effect of wander is evaluated by comparing the simulation results obtained for two cases: one with HVS wander and the other without.
The deployment of automated vehicles (AVs) has many potential benefits, such as reductions in congestion and emissions, and safety improvements. However, two notable aspects of AVs are their impact on roadway hydroplaning and pavement life. Since most AVs are programmed to follow a set path and maintain a lateral position in the center of the lane, over time, significant rutting will occur in asphalt surfaced pavements. This study measured AV lateral wandering patterns and compared them with human driven vehicles. Both wandering patterns could be modeled with a normal distribution but have significantly different standard deviations. AVs have a standard deviation for the lateral traffic wander pattern at least three times smaller than human driven vehicles. The influences of AVs with smaller lateral wandering on pavement rutting and fatigue life were analyzed with the Texas Mechanistic-Empirical Flexible Pavement Design system. The research discovered that AVs would shorten pavement fatigue life by 20%. Additionally, pavement rut depths (RD) increased by 13% and reached critical values of the RD 30% earlier. Deeper ruts formed more quickly leading to thicker water films on wet roads, and consequently, a much higher risk of hydroplaning. The research also calculated maximum tolerable RDs at different hydroplaning speeds. AVs have a much smaller tolerable RD human driven vehicles because of a greater water film in the rutted wheel path. This research thus proposed an optimal AV lateral wandering pattern: a uniform distribution. A uniformly distributed lateral wandering pattern for AVs prolongs pavement fatigue life, reduces pavement RD, and decreases hydroplaning potential.
With the introduction of connected and autonomous trucks (CATs), truck platooning is expected to be more feasible and prevalent. The reported benefits of the truck platooning include reg-ularizing traffic, reducing congestion, increasing highway safety, and decreasing fuel consumption and emission. Truck platooning may, however, decrease pavement longevity because it would cause channelized load application and hinder the healing properties of asphalt concrete. This study proposes a centralized control strategy that converts the pavement-related challenges of truck platooning into opportunities. This strategy leverages the auto-pilot technologies in CATs by optimizing the lateral position of each platoon or group of platoons. The efficiency of the proposed control strategy was demonstrated in a case study. Results showed that pavement life-cycle costs could be reduced up to 50% by controlling the lateral position of the platoons for each day.
Cooperating autonomous vehicles are analyzed. Distributed and coordinated control of autonomous vehicles (automatic ground vehicles, unmanned aerial vehicles, unmanned surface and underwater vessels) has received significant attention during the last years. In this chapter a solution is developed for the problem of distributed control of cooperating autonomous robots which chase a target. The distributed control aims at achieving the synchronized convergence of the autonomous vehicles towards the target and at maintaining the cohesion of the vehicle’s team, while also avoiding collisions between the individuals vehicles and collisions between them and obstacles in their motion plane. To estimate the motion characteristics of the target, distributed filtering is performed. It is shown that to treat the distributed control problem for the cooperating autonomous vehicles a Lyapunov theory-based method is introduced. Moreover, to treat the distributed filtering and state estimation in the multi-vehicle system, decentralized state estimation methods can be applied. The proposed distributed control and filtering method can be used for surveillance and security tasks executed by multi-robot systems. The method for coordinated control of autonomous vehicles is a generic one and thus applicable to various types of autonomous robots, such as automatic ground vehicles, unmanned aerial vehicles, unmanned surface vessels or autonomous underwater vessels. In particular, the chapter treats the following topics: (a) cooperating unmanned surface vessels and (b) Cooperating unmanned ground vehicles
Temperature responses of asphalt pavements are significant, because of their potential influence on pavement structure design and distress prevention, particularly in areas that experience large temperature difference. In this study, a 3D finite element model is developed based on transient heat transfer. The aim is to analyse the temperature responses of the Karamay–Altay Highway in northern Xinjiang, which tends to experience large temperature differences and low temperatures. First, the climatic characteristics and pavement distresses in northern Xinjiang were investigated, and the condition defining a large temperature difference was established. Then, to guide the design of the Karamay–Altay Highway pavement structure, the temperature fields of seven pavement structures were determined. The temperature field of the Str-m structure in the Karamay–Altay area was compared to that in Xi’an. In the Karamay–Altay area, it was observed that Str-4 exhibited the minimum temperature variation at the bottom of the asphalt course and base course. It was clear that the degree of downward temperature transfer was closely related to the structure combination type. The results also suggested that a thicker asphalt layer would effectively reduce temperature effects and diminish distresses resulting from temperature. By comparing of the temperature fields of the Str-m structure in the Karamay–Altay area and in Xi’an, it was observed that pavement temperature fields changed drastically in the case study area, and hence revealed that severe pavement cracks in this area were closely related to abrupt temperature changes, low temperatures and large temperature differences. Hence, it was concluded that in northern Xinjiang, pavement designers should consider the large temperature difference condition very carefully.
The procedures in Mechanistic-Empirical Pavement Design Guide (MEPDG) and Caltrans software program using Mechanistic-Empirical (CalME) methodologies to address wheel wander are relatively simple and based on dividing the wheel wander distribution into a number of segments (say five) of equal areas. Such approaches suffer from a major limitation that the selection of equal segments is arbitrary, and can, therefore, lead to biased results relative to realistic transverse wheel wander distribution. The proposed Monte-Carlo simulation scheme provided cumulative distribution functions for all the critical responses and they in turn were used to estimate pavement performance (or life). The investigation covered a variety of pavement factors that significantly affect pavement performance or life. The factors included are: (1) pavement layer configuration (thin and thick); (2) pavement material properties (unmodified and polymer-modified asphalt mixture); and (3) tyre configurations (dual and wide-base). In this paper, the focus has been on the description of the proposed approach and its application in two of the important modes of failure in asphalt concrete pavements: fatigue cracking (top-down and bottom-up) and rutting. The required traffic-induced pavement strain database needed in the pavement performance investigations was developed using the 3D-Move analysis software. The proposed approach is more appealing than current procedures (e.g. MEPDG and CalME) since the pavement response distributions were derived statistically. The pavement design information presented are in the form of data sets that the pavement engineers and researchers can readily use to assess the impact of wheel wander in terms of many important factors such as pavement layer configuration, non-uniform tyre contact distribution, vehicle speed, etc., that affect long-term pavement performance.
Guide for Mechanistic-Empirical Design of New and Rehabilitated Pavement Structures
ARA, Inc., ERES Consultants Division. (2004). Guide for Mechanistic-Empirical Design of New and Rehabilitated Pavement
Structures. Final Rep., NCHRP Project 1-37A.
Effects of transverse distribution of heavy vehicles on thickness design of full-depth asphalt pavements
- R Buiter
- W M H Cortenraad
- A C Van Eck
- H Van Rij
Buiter, R., Cortenraad, W. M. H., van Eck, A. C., & van Rij, H. (1989). Effects of transverse distribution of heavy vehicles on
thickness design of full-depth asphalt pavements. Transportation Research Record, 1227, 66-74.
Coronavirus Response: Real-World Case for Expanded Autonomous Vehicles Testing in the
- B Donelson
Donelson, B. (2020). Coronavirus Response: Real-World Case for Expanded Autonomous Vehicles Testing in the U.S. JDSupra.
https://www.jdsupra.com/legalnews/coronavirus-response-real-world-case-56295/
Evaluation of the AASHTO 18-Kip load equivalency concept
- I Kawa
- Z Zhang
- W R Hudson
Kawa, I., Zhang, Z., & Hudson, W. R. (1998). Evaluation of the AASHTO 18-Kip load equivalency concept. Center for Transportation Research, The University of Texas at Austin.
Model based predictive control for automated lane centering/changing control systems (US 8,190,330 B2). GM Global Technology Operations LLC
- J Lee
Lee, J. (2012). Model based predictive control for automated lane centering/changing control systems (US 8,190,330 B2). GM
Global Technology Operations LLC, Detroit, MI (US).
Self Driving Freight Trucks - Autonomous Trucks
- C Linder
Linder, C. (2019, December 11). Self Driving Freight Trucks -Autonomous Trucks. Popular Mechanics. https://www.popular
mechanics.com/technology/infrastructure/a30196644/self-driving-truck-cross-country/
Autonomous Vehicle Implementation Predictions: Implications for Transport Planning
- T Litman
Litman, T. (2017). Autonomous Vehicle Implementation Predictions: Implications for Transport Planning. In Victoria
Transport Policy Institute. https://doi.org/10.1613/jair.301
Ontario's Default Parameters for AASHTOWare Pavement ME Design Interim Report -2019
- Ministry Of Transport
- Ontario
Ministry of Transport, Ontario. (2019). Ontario's Default Parameters for AASHTOWare Pavement ME Design Interim Report -2019. https://www.library.mto.gov.on.ca/SydneyPLUS/Sydney/Portal/default.aspx?component = AAAAIY&record = 89a
3febc-f471-4f73-8f3b-4a5c52068874
Illinois Asphalt Pavement Association
- O E Gungor
Preparing for autonomous vehicles
- G Fee