Transport sector constitutes the second largest source of global greenhouse gas (GHG) emissions, being the road transportation the main contributor of these emissions. Efforts in the road sector have traditionally focused on vehicle emissions and infrastructure is typically not included in the emissions account. Road environmental impact is estimated to increase by 10% if the stages of road design, construction, and operation were considered. Previous literature has widely study sustainable practices in pavement design and construction, with little attention paid to maintenance. Current state of practice reveals that pavement managers barely consider environmental performance and their evaluations solely rely on technical and economic criteria. This situation creates the need to incorporate, in an integrated manner, technical, economic, and environmental aspects in the design of maintenance programs. The main objective of this research is to develop a tool for the optimal design of sustainable maintenance programs. Given a maintenance budget, the tool aims to maximize the long-term effectiveness of the network while minimizing GHG emissions derived from the application of maintenance treatments. The capability of the proposed tool is analyzed in a case study dealing with an urban pavement network. In comparison to the traditional maintenance policy, the proposed tool designs maintenance programs that increase the average network condition by up to 22% and reduces GHG emissions by 12%. This application also analyzes the effect of different budgetary scenarios in the technical and environmental performance of the network. This application helps pavement managers in the trade-off between budget and network performance.

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Manuscript Code: 0253 Date of reception/acceptation: 01jan2014/01aug2014Resumen Las infraestructuras de transporte terrestre y particularmente la infraestructura vial son fundamentales en el desarrollo económico y social. El nivel de calidad percibido por el usuario viene determinado, principalmente, por el pavimento. A nivel mundial se invierte anualmente más de 400 mil millones de dólares en la construcción y el mantenimiento de pavimentos; tareas que aumentan en un 10% el impacto ambiental generado por la circulación de los vehículos. Surge así la necesidad de incorporar un enfoque sostenible en la evaluación de alternativas de conservación que considere aspectos técnicos, económicos, medioambientales, políticos e institucionales de forma integrada y armónica a lo largo de su ciclo de vida. La presente investigación tiene por objeto estudiar los modelos y prácticas en la evaluación económica y ambiental de pavimentos para analizar las ventajas y las limitaciones de la práctica actual e identificar oportunidades para mejorar su gestión sostenible. Una de las principales limitaciones identificadas es la escasez de modelos que consideren de forma integrada los aspectos económicos y ambientales. Se detecta la necesidad de modelos que consideren el efecto sobre los usuarios en zonas de trabajo así como el uso de nuevas tecnologías y materiales reciclados más respetuosos con el medio ambiente. AbstractGround transportation infrastructures, particularly road infrastructure, are essential for economic and social development. The quality level that the user perceives is mainly determined by the pavement condition. More than 400 billion dollars are invested globally each year in pavement construction and maintenance; these tasks increase by 10% the environmental impact generated by vehicle operation. Therefore, a sustainable approach should be incorporated in the assessment of preservation alternatives that consider technical, economic, environmental, political and institutional aspects in an integrated manner over their life-cycle. The purpose of the present research is to examine the models and practices for the economic and environmental evaluation of pavement assets, in order to analyze the advantages and limitations of the current state of the practice and identify the opportunities to improve their sustainable management. One of the main limitations identified is the lack of models that consider the economic and environmental aspects integrally. A need for models which consider the impact on users in work zones, as well as the use of new technologies and recycled materials that are more respectful of the environment, has been detected.Palabras Clave: Evaluación del ciclo de vida, administración de activos, pavimentos, sustentabilidad.

Abstract. Society and economy are only two of the dimensions of vulnerability. This paper aims to elucidate the state of the art of data sources, spatial variables, indicators, methods, indexes and tools for the spatial assessment of socio-economic vulnerability (SEV) related to geohazards. This review was first conducted in December 2018 and re-run in March 2020 for the period between 2010 and 2020. The gross number of articles reviewed was 27, from which we identified 18 relevant references using a revised search query and six relevant references identified using the initial query, giving a total sample of 24 references. The most common source of data remains population censuses. The most recurrent spatial variable used for the assessment of SEV is households without basic services, while critical facilities are the most frequent spatial category. Traditional methods have been combined with more innovative and complex methods to select and weight spatial indicators and develop indices. The Social Vulnerability Index (SoVI®) remains the benchmark for the assessment of SEV and a reference for its spatial assessment. Geographic information systems (GIS) is the most common tool for conducting a spatial assessment of SEV regarding geohazards. For future spatial assessments of SEV regarding geohazards, we recommend considering 3-D spatial indexes at the microscale at the urban level and involving the community in the assessments.

Abstract. Insufficient investment in the public sector together with inefficient maintenance infrastructure programs lead to high economic costs in the long term. Thus, infrastructure managers need practical tools to maximize the Long-Term Effectiveness (LTE) of maintenance programs. This paper describes an optimization tool based on a hybrid Greedy Randomized Adaptive Search Procedure (GRASP) considering Threshold Accepting (TA) with relaxed constraints. This tool facilitates the design of optimal maintenance programs subject to budgetary and technical restrictions, exploring the effect of different budgetary scenarios on the overall network condition. The optimization tool is applied to a case study demonstrating its efficiency to analyze real data. Optimized maintenance programs are shown to yield LTE 40% higher than the traditional programs based on a reactive strategy. To extend the results obtained in this case study, a set of simulated scenarios, based on the range of values found in the real example, are also optimized. This analysis concludes that this optimization algorithm enhances the allocation of maintenance funds over the one obtained under a traditional reactive strategy. The sensitivity analysis of a range of budgetary scenarios indicates that the funding level in the early years is a driving factor of the LTE of optimal maintenance programs.

Deterioration indexes that may combine types of surface distresses, serviceability, and structural indicators are commonly used for pavement management at the network level. These indexes differ in the types of deterioration and criteria considered to quantify severity and density of distresses. Most of these indexes were developed for interurban road networks; therefore, their application to urban networks is complex and not representative. For this reason, there is a need for a better understanding of urban pavement behavior to enable collection of the distresses relevant to these types of pavements and development of an overall condition index for urban pavements that represents the mix of the more relevant distresses for use in network analysis. This study is part of a 3-year project developed in Chile: Research and Development of Solutions for Urban Pavement Management in Chile. The main objective of this study was to calibrate and to validate an urban pavement condition index (UPCI) representative of the overall condition of these pavements, according to objective measures of surface distresses and evaluations of an expert panel. The scope of this study included the development of distress evaluation guidelines for asphalt and concrete pavements considering manual and automated surveys, the application of these guidelines in different types of urban networks, and the assessment of these networks by an expert panel. Finally, three UPCI equations were obtained with satisfactory validation for asphalt pavements with manual and automated data collection and for concrete pavements with manual data collection.

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