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Pavement performance models play a vital role in any pavement management system. The Regional Government of Biscay (RGB) (Spain) manages a 1200 km road network and conducts pavement data collections, including the International Roughness Index (IRI) values. The aim of the paper is to develop an IRI performance model for two-lane roads with flexible pavement until the first maintenance and/or rehabilitation activity is performed. Due to the huge amount of available information, a deterministic model was selected. A literature review of deterministic models showed that, apart from age and traffic volumes, the pavement structure is a key factor. Therefore, it was decided to analyze the only road stretches whose entire pavement section was known (surface layer + base + subbase). Various variables related to age, traffic volumes and employed materials were introduced as possible factors. The multiple linear regression model with the highest coefficient of determination and all the variables significant included the real pavement age, the cumulated heavy traffic and the total thickness of bituminous layers. As the material employed in the surface layer could affect roughness progression, a qualitative variable was introduced to consider various surface materials. The model improved its accuracy, indicating that the surface layer material is also an influencing factor on IRI evolution.

Traffic calming measures (TCM) are placed in urban areas to improve road safety, and among them, vertical TCMs are widely employed. Many researches are focused on the influence of the geometry of each measure on speed reduction, but it is demonstrated that drivers forget its effect and speed up after it. Therefore, placing consecutive TCMs can help to maintain a safe area. However, scarce literature can be found about the adequate spacing between them. Hence, the aim of this paper is to analyze the adequate distance between TCMs. Various streets with variable distances and different vertical TCMs were evaluated in Poland and Spain, including raised crosswalks, raised intersections, speed humps and speed cushions. The intermediate point between two TCMs was selected as the place where the maximum speed is achieved. Results showed that there was a good correlation between the speeds at intermediate points and the distance between TCMs, with a determination coefficient around 0.80. For an 85th percentile of the speed under 50 km/h, a maximum distance of 200 m between TCMs is recommended, and for a value of 40 km/h, 75 m.

Road maintenance and rehabilitation are expected to meet modern society's demands for sustainable development. Full-depth reclamation with cement as a binder is closely linked to the concept of sustainability. In addition to the environmental benefits of reusing the existing pavement as aggregate, this practice entails significant technical and economic advantages. In Spain, in the absence of tests specifically designed to determine the behavior of recycled pavements stabilized with cement, these materials are treated as soil-cement or cement-bound granular material. This assumption is not entirely accurate, because this recycled pavement contains some bituminous elements that reduce its stiffness. This study aimed to obtain the relationships between flexural strength (FS) and the parameters that describe the pavement behavior (long-term unconfined compressive strength (UCS) and indirect tensile strength (ITS)) and compare the findings with the relationships between these parameters in soil-cement and cement-bound granular materials. The results showed that the similar behavior hypothesis is not entirely accurate for recycled pavements stabilized with cement, because they have lower strength values-although, this is not necessarily an indication of poorer performance.

Soil⁻cement is an environmentally friendly road construction technique for base and subbase materials, which allows employing soils placed in the right-of-way of the road or in the surroundings, by improving its engineering properties. With this technique, it is possible to reduce the over-exploitation of quarries, the necessity of landfills and the pollutant gas emission due to the reduction of aggregate fabrication and transport. The manufacturing of soil⁻cement is generally controlled by means of the Uniaxial Compressive Strength (UCS) test at seven days, according to the regulations of each country. Nonetheless, one of the properties that best defines the performance of soil⁻cement is the Flexural Strength (FS) at long term, usually at 90 days. The aim of this paper is to develop new equations to correlate the UCS and the FS at long term and the UCS at seven days and at 90 days. Obtained results validate the proposed models and, hence, the flexural strength can be predicted from the Uniaxial Compressive Strength at seven days, allowing, if necessary, correcting measures (recalculation or rejection) in early stages of the curing time to be taken.

Understanding the long-term behaviour of cement-treated base materials is a key factor to improve its design and obtain environmentally friendly pavement base materials. Their characterization requires manufacturing prismatic specimens. However, various authors highlight the absence of standardized test methods for fabricating beams in the field and laboratory, which is not an easy task because it depends on the qualification and experience of the testing team. The aim of this paper is to present a new device and procedure for compacting prismatic specimens of cement-treated base materials. In this research, it was used for compacting soil-cement to simulate its performance as a road base material. This device employs elements that are generally available in a concrete laboratory test, such as a vibrating table or prismatic moulds. Once the procedure was established, and in order to verify its suitability, flexural and compressive strength tests were carried out. Results showed that the values obtained were consistent with this material and, despite the heterogeneity of the material, specimens from the same batch provided similar results and, hence, validated the compaction process. This new compacting procedure can improve understanding of the long-term performance of cement-treated materials from flexural and fatigue tests.

A bibliometric analysis based on Scopus database was carried out to identify the global research trends related to pavement management area from 2000 to 2013, and to improve the understanding of the research topics in that period. The results reveal two stable periods of annual publications, from 2000 to 2002 with an average rate of 27, and from 2003 to 2010 with a value of 51; and a period with an increasing production rate of 20 publications per year after 2010. According to the document-type distribution, articles and conference papers have almost the same contribution. The most productive country was the United States, followed by Canada and China. The research trend in the field of pavement management could be grouped into three main areas. The first one is related to pavement management systems, which attracted the greatest attention, especially optimization processes with various objectives and lifecycle cost analysis. The second group is about pavement performance modeling, where calibration of mechanical empirical models was largely developed. Lastly, data collection had also occupied several papers, mainly about cracking classification. Sustainability aspects in pavement management became an emergent issue. The trending issues in that period, in these categories, were summarized in the paper.