Typical Pavement Research Articles

Temporal Convolutional Network-Based Axle Load Estimation from Pavement Vibration Data

Measuring the axle loads of vehicles with more accuracy is a crucial step in weight enforcement and pavement condition assessment. This paper proposed a vibration-based method, which has an extended sensing range, high temporal sampling rate, and dense spatial sampling rate, to estimate axle loads in concrete pavement using distributed optical vibration sensing (DOVS) technology. Temporal convolutional networks (TCN), which consist of non-causal convolutional layers and a concatenate layer, were proposed and trained by over 6000 samples of vibration data and ground truth of axle loads. Moreover, the TCN could learn the complex inverse mapping between pavement structure inputs and outputs. The performance of the proposed method was calibrated in two field tests with various conditions. The results demonstrate that the proposed method obtained estimated axle loads within 11.5% error, under diverse circumstances that consisted of different pavement types and loads moving at speeds ranging from 0~35 m/s. The proposed method demonstrates significant promise in the field of axle load reconstruction and estimation. Its error, closely approaching the 10% threshold specified by LTPP, underscores its efficacy. Additionally, the method aligns with the standards set by Cost-323, with an error level-up to category C. This indicates its capability to provide valuable support in the assessment and decision-making processes related to pavement structure conditions.

A literature review: asphalt pavement repair technologies and materials

Asphalt pavement is the most widely used type of pavement in the world and is mainly utilised in the construction of infrastructures such as highways, urban roads, parking lots and airstrips. Pavement maintenance technology and materials are gradually developing towards systematisation and diversification with the extensive use of asphalt pavement. Choosing more economical technologies and fast and sustainable materials is the future of asphalt pavement maintenance work. This paper provides an overview of asphalt pavement repair technology and asphalt pavement repair materials. It categorises and summarises pavement repair technologies, which include cost-effective technologies such as crack sealing, overlay, seal coats and hot in-place recycling. Further, it summarises the repair materials applied in repair technologies and compares the performance, cost-effectiveness and sustainability of these materials. The study shows that asphalt and cement are the most commonly used repair materials. The higher-potential, more economical and more sustainable materials for asphalt pavement repair include epoxy resin, polyurethane and hydrogel. The future of asphalt pavement repair requires advancing towards rapid, sustainable, environmentally friendly and economical repairs. A survey indicates that in addition to improving the performance of existing repair materials (e.g. modified asphalt, binder processes, material composition or ratios), attention can be given to new materials such as polyurethanes and hydrogels that have the potential for rapid repair and are low cost. More research can be done to perfect the application of new materials in road engineering.

Verification of The Possibility of Air-void Recovery in RSBS Double-Layer Low-Noise Porous Asphalt Pavement

Radial type styrene-butadiene-styrene double-layer low-noise porous asphalt (RSBS DLPA) pavement is a type of porous asphalt pavement which had high air-void ratio, and well-known to absorb tyre/pavement noise and the rain through the pavement's layer. According to the Korea Meteorological Administration, from July to August in 2022, the daily rain precipitation was more than 100 mm per day and categorized as heavy rain. Due to the high air void ratio in RSBS DLPA pavement, the rainwater will be transferred through the pavement layer. The heavy rain splashing onto the surface pavement is similar to the method using the low water pressure and low-vacuum that our company developed which helps to recover the low-noise porous asphalt pavement. In this study, the CPX method was used to measure the noise level before and after heavy rain to differentiate the noise level. The results showed that the heavy rain had an effect on reducing the noise level. Before heavy rain, the noise level was up to 89.9 dB, while the noise level was decreased to 87.7 dB after heavy rain. It is shown that our cleaning method able to recover the air-void content as same as heavy rain.

Performance Evaluation on the Application of MAST and RCC on a Cambodian Rural Road: A Case Study

Cambodia’s transportation sector has exhibited tremendous growth in the past decades together with its economic advancement. However, these improvements are only focused on the national and provincial roads, leaving the rural roads underdeveloped. A large percentage of the rural roads in Cambodia are unpaved while those paved roads are in deteriorated condition, making these rural roads prone to structural failure when subjected to heavy truck traffic and massive rainfall. Therefore, an innovative pavement material shall be used in the construction and rehabilitation of Cambodian rural roads. In this study, a composite pavement testbed consisting of a roller compacted cement (RCC) base layer and a modified double bituminous surface treatment (DBST), namely multi-layered bituminous surface treatment (MAST), was constructed in Cambodia and its performance was evaluated. To have a point of comparison, the testbed was divided into three sections with varying combinations of surface and base layer: (1) MAST surface with an RCC base, (2) MAST surface with an aggregate base, and (3) DBST surface with an aggregate base. Initially, a visual inspection was conducted to investigate the surface condition of the testbed. To assess the structural capacity, a light-falling weight deflectometer device was used. Meanwhile, the surface roughness was evaluated through the sand patch test. Lastly, the pass-by test was performed to quantify the noise level of the pavement. Based on the results, the proposed composite pavement performed significantly superior to the typical pavement in Cambodia, which is the third section. In summary, the composite pavement with MAST as the surface layer and RCC as the base layer was observed to be suitable for heavy truck traffic loading and the environmental conditions of Cambodia.

Determination of road surface correction factors for CNOSSOS-EU in Ireland

Transport Infrastructure Ireland (TII) is a state agency in the Republic of Ireland. The primary function of TII is to provide an integrated approach to the future development and operation of the national roads network and light rail infrastructure throughout Ireland. TII are designated as the Noise Mapping Body (NMB) responsible for the development of strategic noise maps for all national roads carrying in excess of 3 million vehicles a year. Directive 2002/49/EC (commonly referred to as the Environment Noise Directive, 'the END') relates to the assessment and management of environmental noise. It is the main instrument of the European Union (EU) to quantify noise pollution levels, and trigger action within both Member States and at EU level. The END has the aim of establishing a common approach to the management of noise within the EU. Commission Directive (EU) 2015/996 established the common noise assessment methodology for Europe (CNOSSOS-EU). The CNOSSOS-EU road traffic noise emission model calculates rolling noise for different vehicle categories as a function of speed and frequency. The emission is initially calculated under reference conditions, then corrected for differing situations. For road surfaces which do not align with the reference surface, road surface correction factors should ideally be developed, otherwise a number of default values are provided within CNOSSOS-EU which are taken from the Dutch national noise assessment method, Rmg2012, and therefore contain only surfaces that are common in the Netherlands. For the implementation of CNOSSOS-EU in Ireland, a project was undertaken to develop road surface corrections for at least the three most common pavement types on the TII network with no direct match to the CNOSSOS-EU database. This paper will describe the measurements taken on Irish roads, the resulting road surface corrections, and our conclusions and recommendations for using the road surface corrections.

Finite Element Analysis of Tyre Contact Interaction Considering Simplified Pavement with Different Aggregate Sizes

This study considered the effect of pavement aggregate grain size on tyre–pavement contact interaction during the late stages of pavement skid resistance. First, hemispherical shells 7, 9, and 13 mm in diameter were used to simulate coarse pavement aggregates. Subsequently, a three-dimensional finite element tyre–pavement contact model developed using ABAQUS was employed to analyse the contact interaction between each simplified pavement type and the tyre under steady–state rolling and braking conditions. Finally, the concept of occlusal depth was proposed and applied to characterise pavement skid resistance. The results showed that under steady–state rolling conditions, the peak contact stress of the simplified pavement increased with the pavement mean texture depth, whereas the contact area decreased. Under steady–state braking conditions, the effect of the contact interaction between the tyre and simplified pavement aggregates was ranked in order of superiority as aggregate grain sizes of 9, 7, and 13 mm, indicating that aggregate grain size did not exhibit any correlation with tyre–pavement contact interaction. Additionally, the squares of linear correlation coefficients between the pavement cumulative occlusal depth and horizontal braking force reached 0.921, 0.941, 0.889, and 0.894 for vehicle speeds of 30, 60, 90, and 120 km/h, respectively, indicating that they could be used to assess pavement skid resistance.

Reliability of depleted cement–ground slab with waste granodiorite dust admixture on semi-saturated substrate

There are many types of pavements for roads. For technical roads, one of the most effective and economically advantageous pavement types is chemically stabilized soil pavement. When designing a pavement made of soil admixed with binders, it is necessary to meet the load-bearing conditions while considering the effects of environmental factors. The aims of this study were to optimize the strength parameters of pavement, minimize negative environmental effects, minimize the carbon footprint, and simultaneously dispose of mineral waste materials from the production of asphalt mixes for roads. After testing the strengths of samples admixed with cement or with reduced cement content and the addition of dust, questions arose as to how both materials affect the reliability of the pavement structure. Samples of soil doped with cement and dust were subjected to reliability analyses. Abaqus software with a three-dimensional subgrade model was used for a comparative analysis. The substrates under soil stabilization slabs were subjected to varying saturation states, which affected their vulnerability. In this study, the changes in the saturation characteristics of the subsoils associated with different types of climatic interactions were simulated. The Darcy–Buckingham law was used to describe the flow of liquids through the subsoil. Pavement reliability calculations were performed for a multidimensional space of random variables. The results served as an interesting starting point for recommendations to decrease the use of energy-intensive materials, increase the reuse of waste, and reduce the effects of the strengthening process on the environment.

Analysis of the Effects of Highway Geometric Design Features on the Frequency of Truck-Involved Rear-End Crashes Using the Random Effect Zero-Inflated Negative Binomial Regression Model

Statistical data indicate that trucks are more prone to rear-end crashes, making this an area of concern. The objective of this study is to create a model that analyzes the factors influencing the frequency of rear-end crashes involving trucks (TIRC). To achieve this, researchers identified the most appropriate model as Spatial Zero-Inflated Negative Binomial Regression (SZINB). This model takes into account spatial correlation, which plays a significant role in the occurrences of TIRC on different road segments supervised by each highway ward. The estimation of parameters in the SZINB model has led to key findings that shed light on the factors contributing to a higher likelihood of TIRC. These findings include the increased probability of TIRC on curved roads compared to straight ones, roads that feature open middle islands, six lanes per direction, a slope, right-of-way shoulder width, pavement type, lane width, and a post speed limit. Based on these key findings, this study developed policy recommendations and sample measures aimed at reducing the frequency of TIRC. Implementing measures such as improving the road design on curved sections, optimizing middle islands, and enhancing traffic management on wider roads can help mitigate the risk of crashes involving trucks.

Fly Ash Substitution in Lightweight Concrete for Rigid Pavement Construction on Low-Bearing-Capacity Soil

Peatlands are more likely to be affected by intense precipitation and soil erosion, thus requiring modifications for stabilized soil and subgrade protection. This experimental study aimed to find a suitable pavement type using fly ash, an unutilized byproduct from coal burning processes, for peatland areas with a low bearing capacity. We designed lightweight concrete specimens using 15% fly ash substitution to be incorporated into rigid pavement construction. The concrete quality was assessed through compressive and flexural strength tests performed at the ages of 7, 14, and 28 days in order to shorten the project durations and prevent further traffic delay. The obtained results suggested that the substitution of fly ash in 15% of the lightweight concrete mixture can be taken into account to achieve a mixture of a lightweight concrete that meets the general specification criteria for cement-treated subbases (CTSBs). Furthermore, the utilization of fly ash as a new material is considered substantial in managing existing waste-related environmental problems, as well as soil stabilization and subgrade protection problems for low-bearing-capacity soil areas.

Performance of Permeable Pavement to Filter Stormwater Runoff for Non-Potable Uses in Buildings

Permeable pavement benefits, besides stormwater runoff reduction and groundwater recharge, include stormwater harvesting. As an alternative to water resources scarcity, stormwater that reaches a permeable pavement could be filtered by the same pavement and then used for non-potable purposes in buildings. This work aims to evaluate some types of permeable pavements regarding their performance to remove pollutants from stormwater and decrease runoff. Analyses of infiltration capacity and pollutant concentrations were performed in four permeable pavement models with different types of permeable surface layer (porous asphalt mixture and porous interlocked concrete blocks). Then, the data were used to calculate the “stormwater credits” according to the Minnesota Stormwater Manual. The credits were calculated for volume of runoff, and concentrations of Total Suspended Solids (TSS) and Total Phosphorus (TP). As a result, the models proved adequate to decrease both stormwater runoff and TSS and TP concentrations. Moreover, models with the porous asphalt mixture as a surface layer were more efficient to reduce the concentration of pollutants. However, for the models evaluated in this work, additional treatment is recommended when stormwater harvested from permeable pavements is meant for non-potable uses in buildings.
 Keywords: buildings, stormwater, credits, non-potable uses.

Mechanical response of asphalt steel plastic pavement structure based on finite element simulation and scale load test

To promote sustainable road engineering, the focus is on identifying low-carbon, eco-friendly, and durable materials and structures, as conventional options face performance limitations. Hence, within this paper, we introduce a novel pavement structure, referred to as ASP, which comprises an SMA-13 asphalt mixture, a Q345D steel plate, and acrylonitrile butadiene styrene (ABS) plastic. Initially, we performed a uniaxial compression test to analyze the dynamic mechanical properties and modulus parameters of both the SMA-13 asphalt mixture and ABS plastic. To further investigate the mechanical response of the ASP pavement structure under actual traffic load conditions, we constructed a 1/3-scale model and subjected it to MMLS3 accelerated loading tests to confirm the validity of the established finite element model and verify the performance of the structure. Finally, we developed a full-scale finite element simulation model of the ASP pavement structure and analyzed its mechanical response under loading. The results were then compared to those obtained from typical pavement structures. The results from the MMLS3 accelerated loading test show that both the asphalt and steel plate layers in the ASP pavement structure exhibit similar strain behavior, with consistent peak strains. The strain generated by the underlying structural layer dissipates more quickly in the transverse position, while the steel plate layer and underlying structural layer mainly support the strain generated by the asphalt surface layer. Results from the full-scale finite element simulations indicate that the strain and stress generated between the ASP pavement structure and typical pavement structures are similar. However, the bottom of the steel plate layer in the ASP pavement structure experiences significant three-dimensional and vertical shear stress. In addition, the allowable material value of the bearing layer in the ASP pavement structure, which consists of Q345D steel plate and ABS plastic, is less than 1% compared to the typical pavement structure. This characteristic enables effective transfer and support of the moving vehicle load, highlighting the significant advantages of using steel plate and plastic as pavement materials. To conclude, the ASP pavement's internal structure aligns effectively with real-world conditions, as demonstrated by its load-bearing layer's performance under vehicular loads. This innovative design significantly improves road durability and sustainability, positioning it as a choice for future road construction. These findings provide valuable insights for researching the mechanical response patterns within the ASP pavement's internal structure.

Research of reflective crack in asphalt pavement using SCB specimen and XFEM: From laboratory test to numerical simulation

Reflective cracking is one of the main failure mode of pavement structures, resulting in structure deterioration and reduced traffic safety. This study investigated the cracking behavior of reflective cracks using semi-circular bending (SCB) specimens and fracture tests were conducted to obtain fracture energy, which is the critical parameter of facture calculation, and the reasonability of fracture energy was validated using a numerical model of SCB specimen. Then, a numerical model of typical pavement structure was established and cracking behavior of reflective cracks and related parameters influencing cracking were investigated in detail. The simulation results indicate the main form of reflective crack is mode I and mode II mixed crack, among which mode I takes the dominant position. Among the four investigated influence factors, overloading and long-time loading have a significant influence on the expansion of reflective cracks, while the temperature mainly influences the expansion of mode I crack. The traffic speed mainly affects the direction of crack expansion, while other factors do not have a significant effect on it.

A Study on the Contact Characteristics of Tires-Roads Based on Pressure-Sensitive Film Technology.

Tire-road characteristics are a critical focus of research in the automotive and transportation industries. On the one hand, the research can help optimize tires' structural design; on the other hand, it can analyze the mechanical response of the pavement structure under the vehicle load. In addition, the non-uniformity distribution of the tire ground stress will also have a direct impact on the skid resistance, which determines the driving safety. Due to the limitation of testing technology, the measurement of tire ground pressure was mainly carried out on a flat test platform, ignoring the roughness of the actual pavement surface texture. The tire-road contact characteristics research on the macro-texture and micro-texture of asphalt pavement needs to be broken through. A high-precision pressure-sensitive film measurement system is utilized to examine the actual contact characteristics between two types of automobile tires and three types of asphalt pavement in this paper. The influence law of pavement texture and patterned tires on the contact area and stress was explored, and the concentration effect of tire-road contact stress was evaluated. The results indicate that the contact area of grounding tires exhibits a nearly linear relationship with tire inflation pressure and load. Notably, the change in load has a more significant influence on the contact area than tire inflation pressure. On asphalt pavement, the contact reduction rate decreases by approximately 5-10% for block pattern tires and 10-15% for longitudinal pattern tires. Furthermore, as the texture depth of the pavement increases, the contact area between tires and the pavement texture decreases. The actual tire-road interface experiences significant stress concentration due to the embedding and meshing effects between the tire and road surface. Even on a flat steel surface, the peak stress at the edge of the tread block exceeds the 0.7 MPa design load, which is about 2.5-3 times higher than the design uniform load. The peak stress between the tire and asphalt pavement reaches 4-10 times the design uniform load, with a rising trend as the pavement texture depth increases. This study can provide relevant experimental technical support for tire design and functional design of asphalt pavement.

Study on green concrete (porous concrete) sustainability in order to support the sustainable construction in Indonesia

Currently implementation progress of green concrete (porous concrete0 is still very slow. The sustainable construction launched by the government has also not received a positive response from the construction sector. Greenery Open Spaces (RTH) and urban spatial planning in Indonesia have not accommodated the type of water-friendly pavement (porous concrete). Buildings that must meet the 30% of Green Base Cooeficient (KDH) also have not included the criteria for water-friendly concrete pavements. From the results of the Multi-Dimensional Scaling (MDS) analysis using Rapfish-R, it is known that the sustainability status of porous concrete is at a score of 71.9 (sufficiently sustainable). There is no leveraging factors from the ecological dimension. Leverage from economic dimensions, i.e.: added value for customer, durability and installation costs. Institutional dimensions, i.e.: application of ecolabels, product standards and criteria for RTH and KDH. Socio-technical dimension, i.e.: public understanding and perception, certification scheme, role of media, design and maintenance. From this leveraging factors, then can be formulized the strategy and roadmap for supporting the sustainable construction related to green concrete application

Evaluation of low-noise-drainage pavements with varied aggregate sizes: A case study in South Korea

This research addresses the need for quieter and safer road environments by evaluating low-noise-drainage pavements with varying coarse aggregate sizes. Thorough physical property tests were conducted on pavements with aggregate sizes of 8 mm, 10 mm, 13 mm, and 19 mm. Field tests assessed pavement characteristics over service years, including permeability, roughness, friction resistance, and road traffic noise. Notably, the 19 mm pavement exhibited optimal permeability, highlighting efficient water drainage. The 13 mm variant demonstrated superior roughness, indicating enhanced durability. Surprisingly, the 10 mm pavement's roughness improved after seven years. Slip resistance met standards in all but the 19 mm type, with the 10 mm and 13 mm pavements excelling in promoting road safety. Noise assessment showed an 8.7 dB(A) reduction in the low-noise-drainage pavement post-construction, but age-related effects were observed. Recognizing the potential for performance decline, this research emphasizes dedicated maintenance practices. This study offers insights for various pavement types, shaping designs, strategies, and noise mitigation measures for safer roads.

Effect of type and aggregate gradation on the functional properties of porous asphalt (case study of Iran)

Porous asphalt mixtures are gaining popularity due to their ability to effectively drain surface water and mitigate traffic noise in regions with high rainfall. However, compared to conventional asphalt pavements, these types of pavements with high void content necessitate specific guidelines for achieving an optimal mix design. The performance characteristics of porous asphalt mixtures are notably influenced by the grading and composition of materials, especially with regards to their resistance to moisture damage. This study aimed to investigate the properties of porous asphalt mixtures using limestone and siliceous aggregates with varying gradations, while maintaining bitumen contents of 5% and 6%. In accordance with the regulations set forth by the National Center for Asphalt Technology, the findings indicate that siliceous-based aggregates exhibit improved void characteristics (increased by 3%) and permeability (increased by 11%). However, they also display reduced resistance to moisture-induced failures (decreased by 4%). On the other hand, adhering to the gradation recommendations provided by the National Asphalt Pavement Association guidelines, except for a slight decrease of 3% in moisture sensitivity, yields an overall enhancement of 25% in other performance characteristics. To analyze the data, statistical methods were employed, resulting in regression models with a minimum R2 value of 0.97. These models helped determine the optimal binder percentage for different aggregate types and gradations, providing valuable insights for practical implementation.

Prediction of Pavement Overall Condition Index Based on Wrapper Feature-Selection Techniques Using Municipal Pavement Data

Municipalities make significant efforts with limited resources to collect pavement condition data. Overall Condition Index (OCI), which uses the pavement surface evaluation and rating manual to identify roadways needing repair, is a convenient and common way of pavement condition assessment. Many data used in assessing the OCI are collected from fieldwork. Some data features give little insight into road conditions, and one feature may provide similar information to another; thus, effective data-collection resources can be optimized by selecting which data feature to keep and which to discard. In addition, the OCI reflects how local agencies highlight the important variables driving their pavement-management investments. It is also a reflection of the triggers that they use to propose various treatment strategies. This research aimed to evaluate pavement distresses in West Des Moines, Iowa, using machine-learning methods, and determine which combination of distresses and their distress proportions can accurately predict the OCI class of a particular pavement type. The wrapper feature-selection methods were used, fitting their results to classification-tree models. Automatic feature selection, using Featurewiz, was also considered to select the desired number of variables. Feature parameters were screened for OCI prediction using the mean decrease impurity, and the results could be used to model classification that may be used for year-long predictions. Results showed that an effective OCI estimate methodology could be determined with significant accuracy with fewer features.

Clog-Resistant Permeable Pavement: Methods of Performance Measurement

Permeable pavements are considered to be one of the effective measures for LID (i.e. Low Impact Development) and SUDS (i.e. Sustainable Urban Drainage System) globally. The major three types of permeable pavements are (a) pervious concrete (PC), (b) previous asphalt (PA), and (c) permeable interlocked concrete paver (PICP). The performance of all types of permeable is satisfactory at the start of the service life but greatly reduced if not maintained on time. Considering the long lengths of the pavements, measurement of permeability at different locations is a cumbersome and tedious task. Therefore, ease of performance and realistic results are of vital importance. In this study, ASTM C1701/C1701M—17a single ring infiltrometer, Stormwater Infiltration Field Test (SWIFT), and NCAT permeameter Methods are discussed in detail and examined for their relative ease of setting-up, versatility and performance. It is concluded that ASTM C1701/C1701M—17a single ring infiltrometer is the most versatile, easy to set up and produces accurate results.

Superposition of populations in multi-objective evolutionary optimization of car suspensions

The design of the suspension model of road cars is extremely important for both driver comfort and safety. Road traffic injuries are currently the eighth leading cause of death worldwide and are predicted to become the seventh leading cause of death by 2030, according to the World Health Organization (WHO). Among other factors, road infrastructure is one of the most important factors to consider when designing the suspension model, especially as autonomous driving becomes more popular. In addition, there is a growing need to test and study the impact of road roughness and pavement type on autonomous vehicles (AVs). This work provides the following contributions: a platform for suspension system optimization–flexible, highly parameterizable and rich in applications. Our solution implements, tests and optimises the 2, 3 and 4 degrees of freedom (DOF) quarter-car models (QCM) with linear seat suspension and the 5 DOF half-car model (HCM), respectively, based on random road profiles generated according to ISO 8608 standards. In addition, many multi-objective optimization (MOO) algorithms have been implemented and applied in isolation to see their comparative performance (in terms of Pareto fronts, hypervolume, coverage, spread, and epsilon), but most importantly we have also introduced a meta-optimization technique by super-positioning Non-dominated Sorting Genetic Algorithm II and Strength Pareto Evolutionary Algorithm 2, where each of the algorithms, running concurrently, produces a percentage of the total number of individuals in a generation, percentage that is calculated according to the solution quality of the individuals in the previous generation. The experimental results were obtained by simulating the optimal configurations generated by the MOO heuristic algorithms on different categories of cars (small/medium). Finally, the Taguchi method and regression analysis were used to evaluate the effects of specific parameters on system responses such as sprung mass acceleration and displacement. The Taguchi simulation was performed to experimentally validate the results obtained by metaheuristic optimization methods.

Lifetime Performance of Polymer-Modified Bitumen in Swedish Roads Evaluated With Survival Analysis

This study uses survival analysis to estimate the lifetime of Swedish asphalt paved roads. The roads were separated by binder type, such as unmodified bitumen and polymer-modified bitumen (PMB). Road pavements with PMB were compared to equivalent roads with regard to annual average daily traffic, heavy vehicles, road type, road width, speed limit, construction year, region, bearing capacity, pavement type, stone size, and rut bottom distance. The analysis was based on almost 500,000 records of pavement maintenance and road condition measurements from the Swedish Transport Administration’s Pavement Management System database, dating back as far as the 1970s. The results showed that PMB in the surface layer was expected to extend road lifetimes by 15% compared with bitumen. PMB in the underlying layer gave an 8% increase in life expectancy compared with unmodified bitumen. PMB in both layers gave a 24% increase in expected road lifetime compared with unmodified bitumen in both layers.