Development of a Sustainable Management System for Rural Road Networks in Developing Countries

Rural roads play a crucial role in the economic and social development of societies, linking rural communities to education, health services and markets. During the last decade, considerable efforts have been made to evaluate the benefits of rural road investment in developing countries. Although outputs of these studies have led to a global rethinking of traditional road appraisal methods, limited attempts have been made to integrate these findings to the rural road management process. For the sustainable management of rural roads, social, institutional, technical, economic and environmental aspects should be considered under a long term perspective. The current practice in developing countries is that only some of these key sustainable aspects are being considered in the management process. In addition, rural roads maintenance management is commonly performed under a short term basis, not considering the life cycle costs and benefits in the economic analysis and project prioritization. Available management tools and studies have essentially focused their efforts on improving technical and economic aspects of low-volume roads. Whereas, the common practice observed in face of limited resources and lack of technical skills is that decisions are made under a political short term perspective. This research is directed at the development of an applied and practical system for the sustainable management of rural road networks in developing countries. The approach considers the development of all components required by the proposed management system and their integration into a practical and easy-to-use computer tool. To achieve this goal a sustainable framework for rural roads management was first developed, where system components and modules were defined. A network level condition evaluation methodology was selected and validated. Long term condition performance models were calibrated from the probabilistic analysis of field data. Optimal maintenance standards were developed under a cost-effectiveness approach. A long term prioritization procedure was developed to account for sustainable aspects of rural roads in the management process. A computer tool was finally developed to integrate the system components and display them in a friendly interface for potential users. The tool was programed in Visual Basic, considering Microsoft Excel interface. The computer tool considers the four system components: Input Data, System Modules, Network Analysis Interface and Output Data. System Modules include Condition Performance Module, Network Maintenance Module and Long Term Prioritization Module. For each of the system components and modules a separate worksheet has been included in the computer tool. The tool is centered on the Network Analysis Interface, which interacts with the other three system components. The user enters network data in the Input Data interface and may adjust information in System Modules considered if the network under study has differences to predefined conditions of. Adjustments to System Modules can be performed by the user, however it is advised that prior calibration is required for the successful analysis of the network. The management system was applied and validated in two rural road networks in developing countries located in Chile and Paraguay. Sensitivity analysis was carried out to assess the impacts of input parameters in the performance of developed system. As a result of the research an adaptable and adoptable sustainable management system for rural networks was developed to assist local road agencies in developing countries.1 yea

Towards a sustainable optimization of pavement maintenance programs under budgetary restrictions

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.The authors gratefully acknowledge members of the research group at the Pontificia Universidad Catolica de Chile for providing information concerning the case study analyzed in this paper. The research team acknowledges Fondef/Conicyt 2009 for funding the project "Research and Development of Solutions for Urban Pavement Management in Chile" (D0911018) and the National Research Center for Integrated Natural Disaster Management CONICYT/FONDAP/15110017. Funding from CONICYT (CONICYT-PCHA/Doctorado Nacional/2013-63130138) to support this work is sincerely appreciated.Torres Machí, C.; Pellicer Armiñana, E.; Yepes, V.; Chamorro, A. (2017). Towards a sustainable optimization of pavement maintenance programs under budgetary restrictions. Journal of Cleaner Production. 148:90-102. https://doi.org/10.1016/j.jclepro.2017.01.100S9010214

Review article: The spatial dimension in the assessment of urban socio-economic vulnerability related to geohazards

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

Optimal pavement maintenance programs based on a hybrid Greedy Randomized Adaptive Search Procedure Algorithm

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

Modelos y prácticas actuales en la evaluación económica y ambiental para la gestión sostenible de redes de pavimentos

[EN] Ground 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.[ES] 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.Authors gratefully acknowledge members of the research group at the Pontificia Universidad Católica de Chile for their resources during the study. The research team acknowledges Fondef/Conicyt 2009 for funding the project “Research and Development of Solutions for Urban Pavement Management in Chile” (D09I1018) and the National Research Center for Integrated Natural Disaster Management CONICYT/FONDAP/15110017. Funding over Conicyt (CONICYT-PCHA/Doctorado Nacional/2013-63130138) to support this work is sincerely appreciated..Torres Machí, C.; Chamorro, A.; Yepes, V.; Pellicer Armiñana, E. (2014). Current Models and Practices of Economic and Environmental Evaluation for Sustainable Network-Level Pavement Management. Revista de la Construcción. 13(2):49-56. http://hdl.handle.net/10251/55539S495613

Improving cost performance in design-bid-build road projects by mapping the reasons for cost overruns into the project phases

Design-Build (DB) is an alternative project delivery system that has shown to be better in controlling cost growth than the traditional Design-Bid-Build (DBB) system. However, some road administrations are not legally allowed to implement DB and keep using DBB with consequent disadvantages, such as having high-cost overruns. There is a need, therefore, to provide road administrators delivering DBB projects with research-based mitigation measures that can help them to minimize the main reason for cost overruns. To this end, this study identifies the main reasons for cost overruns in the design, the procurement and the construction phases of DBB road projects and point out to the specific elements of DB project delivery that might help to minimize these reasons. To identify the reasons, an exploratory content analysis was performed on interviews conducted with 41 professionals involved in road project management in Chile. Literature review and document analysis of DB were used to analyze the identified reasons under the framework of the DB practice in the United States. The results showed that four elements based on the DB approach might be used to minimize cost overruns in DBB projects: (1) in the design phase, road administrators should consider the early integration of the constructor&rsquo;s expertise. In the procurement phase, they should establish (2) instances for effective information exchange and (3) a goal-oriented selection process. Overall, road administrators should consider (4) establishing a one-point of high-level accountability for the design, the procurement, and the construction phases. This study will serve DBB road administrators to start the transition from DBB to more collaborative approaches that will help to minimizer cost overruns and, therefore, to improve the project cost performance.</p

Importance of Noncost Criteria Weighing in Best-Value Design–Build US Highway ProjectsE DESIGN-BUILD U.S. HIGHWAY PROJECT

United States highway agencies use best-value procurement with a fixed price to select design-builders.&nbsp; This method enables public agencies to choose the best proposer by assessing several factors in addition to price. Theoretically, considering cost and non-cost factors in the selection enhances the probability of selecting the proposer that provides the best value for each dollar spent.&nbsp; However, bidding results from the last 15 years show that 80% of best-value procurements are awarded the proposer with the lowest bid.&nbsp; The selection seems thus to be biased towards price. This research explores the balance between cost and non-cost components in best-value procurement by identifying how weights and scores influence the selection. The goal of this analysis is to determine the ranges of weights that better balance cost and non-cost factors in the weighted criteria best-value procurement. This study characterized a first-of-a-kind dataset of 882 non-cost scores and 1,158 cost scores from 347 best-value highway projects. The study applied simulation to the weighted criteria award algorithm to explore the balance between cost and non-cost factors and derive recommendations about how to make non-cost factors more influential. The results show that weight of cost higher or equal to 57% will result in a lowest price selection. Highways agencies should be aware of how weights and scores impact the best-value selection so that they can align these elements with their selection objectives.</p

Structured Approach for Best-Value Evaluation Criteria: US Design–Build Highway Procurement

In best-value procurement, current practice shows that cost is frequently more influential than noncost factors, and consequently, the lowest bidder is chosen in most cases; thus, a best-value selection is not achieved. Design-builders cannot offer the best value in their proposals if evaluation criteria do not show precisely what constitutes best value and how best value is scored. Thus, the aim of this research is twofold: first, to identify how highway agencies articulate evaluation criteria and, second, to propose a structured approach that enhances current practice on writing evaluation criteria. Through the lens of decision analysis, the researchers conducted a content analysis on 540 evaluation criteria included in 98 requests for proposal (RFPs) from 21 states across the United States. The study showed that 43% of evaluation criteria were generic, 53% used a generic constructed scale, and 4% assigned points or levels directly. These three groups represent different levels of specificity in writing evaluation criteria. Building upon these levels and on decision analysis theory principles, this research proposes a structured approach to support highway agencies in the process of crafting evaluation criteria. More precise and specific evaluation criteria will enhance the proposals&rsquo; ability to offer the best value, which, in turn, will enhance the best-value selection process as a whole. &nbsp;</p

Sustainable Pavement Management. Integrating Economic, Technical, and Environmental Aspects in Decision Making

Sustainability, which is founded in the reconciliation of economic, environmental and social aspects, has become a major issue for infrastructure managers. The economic and environmental impacts of pavement maintenance are not negligible. More than 400 billion USD are invested globally each year in pavement construction and maintenance. These tasks increase the environmental impacts of vehicle operation by 10%. Because maintenance should be technically appropriate, it is important to integrate technical, economic and environmental aspects in the evaluation of maintenance alternatives over the life cycle of pavement. However, these aspects are normally assessed in different units that are difficult to combine in the decision-making process. This research examines and compares different methods for the integrated consideration of technical, economic and environmental aspects. This study aims to assist highway agencies, researchers and practitioners with the integration of these aspects for the sustainable management of pavement. For this purpose, a set of maintenance alternatives for asphalt pavements are evaluated. Different methods for the integration of these aspects are explored, leading to recommendations for the most suitable methods for different scenarios. Because of this analysis, the Analytic Hierarchy Process (AHP) is recommended when the number of alternatives is reduced. In these situations, the AHP leads to results that are similar to those of the Weighting Sum and Multi-Attribute approaches that are frequently used for intuitive selection. However, when the number of alternatives is large, pair comparison becomes difficult when using the AHP and the Weighting Sum method becomes more appropriate.The authors gratefully acknowledge the scholarship awarded by the Vicerrectoria de Investigacion from the Pontificia Universidad Catolica de Chile and funded by the Ministerio de Educacion de Chile. The research team acknowledges FONDEF-Comision Nacional de Investigacion Cientifica y Technologica (CONICYT) 2009 for funding the project Research and Development of Solutions for Urban Pavement Management in Chile. In addition, the authors sincerely appreciate the funding provided by CONICYT and the National Research Center for Integrated Natural Disaster Management.Torres Machí, C.; Chamorro, A.; Pellicer Armiñana, E.; Yepes, V.; Videla, C. (2015). Sustainable Pavement Management. Integrating Economic, Technical, and Environmental Aspects in Decision Making. 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