This study evaluated the field performance of asphalt pavements with and without slurry seal applications, developed performance models for asphalt pavements without slurry seals and asphalt pavements receiving slurry seals at various times following construction, and identified the optimum time for applying slurry seals on asphalt pavements in the Washoe County, Nevada, region. This determination was achieved by evaluating the long-term pavement performance data collected with the MicroPAVER system for the past 15 years and the cost-effectiveness of slurry seals applied to new and existing flexible pavements at Years 0, 1, 3, 5, 7, and 9 after construction. This study found that applying slurry seal immediately after or 1 year after construction of the asphalt layer is not effective in regard to the benefit to users and the benefit–cost ratio for the agency. The optimum time of applying slurry seal depended on the type of construction activity. For newly constructed pavements, the optimum time to apply slurry seal was 3 years after construction. For pavements subjected to overlays, the optimum time to apply slurry seal was between 3 and 5 years after construction. However, for uniformity purposes, it was recommended that the agency apply slurry seal 3 years after construction of the asphalt layer for both new and overlay constructions.

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.

Heavy snowfall is the most influential factor in the interruption of road vehicular transit during the winter months, sometimes even causing inaccessibility to certain areas. Traditional maintenance strategies address this issue with mechanical solutions combined with the implementation of “de-icing salts”. However, these “de-icing” salts can cause severe damage to the local ecosystem and represent an unsustainable solution to the removal of snow. In order to offer an alternative to the use of “de-icing salts” in roadway maintenance, new environmentally friendly strategies need to be explored. The objective of this paper is to evaluate the thermal performance of electroconductive asphalt mortars under the effect of time-varying magnetic fields, with the aim of using these materials for anti-icing and de-snowing applications on roads. The electroconductive mortars studied were manufactured using the metallic fibres obtained from recycled pneumatic end-of-life vehicle tires. These innovative roadway mortars were tested by measuring the temperature changes produced during and after the activation of the time-varying magnetic field, in a 2-layer system composed of an electroconductive asphalt layer under a conventional bituminous surface course. The results revealed that road temperatures can be controlled depending on the intensity of the magnetic field, the content of metallic fibres and the thickness of the road surface course. Electroconductive mortars might therefore provide a functional alternative for maintaining serviceable roads during snowy winters.

In the coming years, asphalt materials will face significant challenges due to the demand for smart multifunctional materials in transportation infrastructures, designed under sustainability criteria. Asphalt pavements will not only have to contribute towards the provision of an adequate surface for the transportation of different types of vehicles, but will need to do so considering the increased loads that they will have to support, as well as the extreme weather conditions resulting from climate change. These pavements will also need the capacity to interact with autonomous vehicles and provide information to the users and maintenance agencies regarding traffic data or performance levels. This paper describes how mechanomutable asphalt materials (MAMs) could enhance the properties of asphalt materials, enabling their use as a solution for smart infrastructures.

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.

Mechanomutable asphalt materials (MAMs) are being developed as a key contribution towards the evolution of smart roads. MAMs are composed of a matrix of asphalt materials modified with metallic fibres that can be activated with magnetic fields. By controlling the physical domain of the magnetic fields, it is possible to manage the mechanical performance of MAMs, and consequently transform the pavement into a smart structure that is capable of reacting efficiently to the requirements of traffic and weather. This paper describes the results obtained from a study conducted using a resonance frequency test to evaluate the mechanical performance of the dynamic modulus of various sizes of specimens of MAM mortars under the activation of various intensities of magnetic field. MAM mortars containing two different quantities of metallic fibres were used to manufacture specimens of two different sizes that were evaluated under various temperatures. The findings indicate that the dynamic modulus of the MAMs is affected by both the intensity of the magnetic field applied and the fibre content, but not by the size of the specimen, therefore, just the two first aforementioned variables should be considered in the design of MAMs for the construction of smart roads.