Planning road maintenance and development activities, prioritizing road construction, reconstruction and rehabilitation works, performing project economic evaluations, forecasting road operation expenditures and road user effect always requires prediction of pavement behaviour. For this purpose models of pavement deterioration are used. Commonly they are integrated in more sophisticated computational systems, known as Pavement Management systems (PMS) and Highway Development and Management systems (HDM). The implementation of these systems started in Lithuania shortly after the Re-establishment of the Independence. This was triggered by the violent drop in financing of the road sector, forcing to change obsolete road management strategy and planning approach. The need for project economic evaluations, transport modelling and long term pavement performance forecasts grew up after Lithuania joined the European Union and this brought the opportunity for financing road infrastructure projects from the EU funds. At present only on the Lithuanian state road network the total value of implemented projects, justified by evaluations and modelling with PMS, amounts to about 500 million Litas annually. Any Pavement Management System is just as good as the models within it, used for pavement deterioration prediction. The performed test calculations show that prediction models, currently used for this purpose in PMS we have in Lithuania, are of doubtful accuracy and have to be improved... [to full text]

Thesis. (M. Tech. (Faculty of Engineering and Technology, Dept. of Civil Engineering))--Vaal University of Technology, 2011 / In the past thirty years there has been a rapid deterioration of the road network in South Africa. As an attempt to address this challenge, a study was conducted on R34 between Vrede and Bothmas Pass Border. The aim of the study was to develop a pavement management system for road network maintenance to serve as a decision support tool to assist to improve the efficiency of making decisions, provide feedback as to the consequences of these decisions, ensure consistency of decisions made at different levels and improve the effectiveness of all decisions in terms of efficiency of results. The study focused on developing and testing pavement management system for road network maintenance. Consequently, visual condition inspections, non-destructive and semi-destructive tests were conducted on the field, data acquired, processed and analysed in accordance with guidelines stipulated in the Draft Technical Recommendations for Highways (TRH) 22 in order to draw conclusions. The data acquired included the surfacing assessments, structural assessments, functional assessments, traffic surveys, riding quality, falling weight deflectometer, mechanical rutting, material investigations and dynamic cone penetration. After analysis of the data, visual condition index was then calculated to be 40%. Visual condition index was then used to determine the action required towards rehabilitating the road. After consultation with guidelines contained in the TRH22, it was concluded that the pavement treatment needed for the road was Rehabilitation. It was then concluded that PMS developed would provide key performance indicators to assist with decision support system and that it is also suitable for road network applications ranging from national roads, provincial roads, regional or district arterial and collector / distributor networks in SA. The municipalities and other road maintenance agencies were then recommended to utilise the “easy to use” developed pavement management system as a decision support tool in their maintenance programmes.

Τα τελευταία χρόνια στις περισσότερες χώρες έχει ολοκληρωθεί η κατασκευή οδικών δικτύων και το ενδιαφέρον των φορέων οδοποιίας έχει στραφεί στη διαχείριση των υφιστάμενων οδικών κατασκευών. Το κυριότερο τμήμα της Διαχείρισης Οδικών Δικτύων καταλαμβάνει η Διαχείριση Οδοστρωμάτων. Τα Συστήματα Διαχείρισης Οδοστρωμάτων έχουν ως στόχο την οικονομική διαχείριση των οδοστρωμάτων και χρησιμοποιούν τεχνητή νοημοσύνη για να καταλήξουν στη βέλτιστη και οικονομικά αποδοτικότερη κατανομή των διαθέσιμων πόρων. Το ευφυές σύστημα που διαθέτουν καταφέρνει να εντοπίζει τη βέλτιστη λύση που ελαχιστοποιεί το κόστος συντήρησης αλλά δεν λαμβάνουν υπόψη τους το αντίκτυπο της επιδείνωσης της κατάστασης του οδοστρώματος στο χρήστη και στο περιβάλλον. Στην παρούσα εργασία χρησιμοποιείται ένας γενετικός αλγόριθμος και αναζητείται η βέλτιστη λύση που ελαχιστοποιεί το γενικευμένο κόστος, το οποίο περιλαμβάνει το κόστος συντήρησης, το κόστος του χρήστη εξαιτίας της κατάστασης του οδοστρώματος και το περιβαλλοντικό κόστος. Τα δεδομένα του προβλήματος αφορούν την κατάσταση των τμημάτων που πρόκειται να συντηρηθούν, το είδος της οδού στο οποίο ανήκουν τα τμήματα οδοστρώματος, τα στοιχεία φθορών κάθε τμήματος, τα διαθέσιμα είδη συντήρησης, το ύψος της χρηματοδότησης και τα κυκλοφοριακά χαρακτηριστικά της περιοχής στην οποία βρίσκονται τα υπό συντήρηση τμήματα. Ο αλγόριθμος κατασκευάζει γονίδια επιλέγοντας είδος συντήρησης για κάθε τμήμα και για κάθε χρόνο συμπεριλαμβανομένης και της επιλογής να μην γίνει καμία συντήρηση σε κάποιο χρόνο. Τα γονίδια ελέγχονται με βάση περιορισμούς που έχουν τεθεί από τα μοντέλα φθορών κάθε τμήματος και επιλέγονται να μεταφερθούν στην επόμενη γενιά αυτά που συνδυάζουν το ελάχιστο κόστος και το μέγιστο επίπεδο λειτουργικότητας στο οδόστρωμα. Η διαφορά του μοντέλου σε σχέση με τα κοινά συστήματα διαχείρισης οδοστρωμάτων έγκειται περισσότερο στις υπολογιστικές απαιτήσεις του συστήματος καθώς η εφαρμογή γενετικού αλγορίθμου οδηγεί γρηγορότερα σε λύση από ότι οι κλασικές μέθοδοι βελτιστοποίησης όπως π.χ. ο γραμμικός προγραμματισμός. Η καταλληλότητα και η ευκολία προσαρμογής των γενετικών αλγορίθμων σε προβλήματα διαχείρισης οδοστρωμάτων επαληθεύεται στην παρούσα εργασία. Το σύστημα καταφέρνει να εντοπίζει το βέλτιστο χρόνο με την οικονομικότερη συντήρηση του κάθε τμήματος του οδικού δικτύου και την πιο φιλική λύση για το χρήστη της οδού και το περιβάλλον. / In recent years the focus of the transportation authorities, researchers and practitioners is being shifted from the construction of new roads to the management of existing road structures and especially to road pavements. Pavement Management Systems are widely used and are continuously being improved because they can lead to considerable fund savings and/or to higher levels of service of road pavements. In this work, a model for pavement maintenance and rehabilitation planning and optimal resource allocation is presented. The objective function aims at minimizing a generalized cost parameter which includes a number of monetary cost components and no monetary impacts. In particular, the objective function consists of the following components: (1) agency cost (the cost of applying the selected maintenance and rehabilitation strategy), (2) user costs (they include vehicle operating cost for fuel consumption, vehicle maintenance and depreciation, traffic delay cost, accident cost, discomfort cost, and delay cost due to maintenance works and (3) environmental impact costs due to traffic pollution and noise. The above cost components are considered with regard to the existing pavement condition levels which are represented by the PSI index. Pavement condition deterioration is assessed through deterministic models that have been developed earlier by our team based on expert opinions and fuzzy systems considering pavement related and traffic parameters, i.e., pavement age, pavement strength, pavement construction quality and traffic loads. The maintenance and rehabilitation treatments are considered with regard to their cost and effectiveness characteristics. Besides the pavement condition deterioration functions, other constraints of the model include budgetary availability (total and individually for different highway groups), threshold values for the minimum accepted pavement condition levels (by highway class), desirable pavement condition levels (by highway class), maintenance and rehabilitation treatment applicability and effectiveness, etc. Due to the size and complexity of the problem (non linear functions), a genetic algorithm has been used as an optimization tool. The algorithm forms solutions by considering applicable maintenance treatments at each pavement section and year within the analysis period. Each solution is checked against all constraints to ensure the feasibility of the solution. No feasible solutions are discarded and new solutions are generated until the required offspring solutions are obtained. The optimization runs over several road sections with different traffic and pavement condition characteristics and within a time span of 10 years. The budgetary or the minimum accepted pavement condition constraints can be altered in order to get a Pareto-front set of optimal solutions for a particular application. Preliminary evaluation indicates that the model provides reasonable results in terms of the appropriate selection of maintenance and rehabilitation treatments and the time of application.

O número de concessões rodoviárias tem aumentado em todo o mundo. Somente no Brasil, desde 1995, três etapas de concessão já foram realizadas pelo governo federal. No estado de São Paulo, as concessões estão em sua segunda etapa. Uma das principais justificativas para as concessões rodoviárias é a melhoria da condição dos pavimentos. Sendo assim, este trabalho buscou avaliar os benefícios oriundos da melhor conservação dos pavimentos, em termos da irregularidade longitudinal, diretamente relacionada com os custos de operação dos veículos (custos dos usuários: consumo de combustível, desgaste de pneus, tempo de viagem etc.), comparando com os custos por pagamento de pedágio. Para tanto, foram selecionados, através da análise de cluster, três trechos distintos, de tal forma que se tivesse, pelo menos, um segmento do modelo da ANTT da primeira etapa, um segmento do modelo da ANTT da segunda etapa e um segmento do modelo da ARTESP. Os custos de operação dos veículos foram determinados com uso do software HDM-4 e a análise econômica considerou o Valor Presente Líquido (VPL), a Taxa Interna de Retorno (TIR) e a Relação Benefício/Custo (B/C). As alternativas consideradas na análise simularam as exigências contratuais presentes no programa CREMA e no Programa de Exploração da Rodovia (PER) da ANTT. A condição \"base\" para as análises simulou um cenário limite para intervenção no pavimento, onde a mesma só ocorria com irregularidades muito elevadas. Após a realização das simulações, concluiu-se que o método do VPL era o mais adequado para as análises, pois todos os trechos apresentaram custos aos usuários maiores do que os benefícios observados. Ao se realizar análise complementar, com limites de irregularidade ainda maiores para a condição \"base\", somente o modelo da ANTT da segunda etapa justificou economicamente a concessão, do ponto de vista dos usuários. Conclui-se, portanto, que existem evidências de que as concessões rodoviárias no Brasil não têm melhorado a condição dos pavimentos a ponto de ser justificada economicamente, decorrendo a sugestão para que as próximas concessões acarretem custos de pedágio menores ou apresentem um maior número de obras com impacto significativo na redução do tempo de viagem e no aumento da segurança dos usuários. / The number of road concessions has increased worldwide. Only in Brazil, since 1995, three concession stages have already been carried out by the federal government. In the state of São Paulo, the concessions are in its second stage. One of the main justifications for road concessions is the improvement of pavement condition. Therefore, this study sought to evaluate the benefits of better pavement conservation in terms of longitudinal roughness, directly related to vehicle operating costs (user costs: fuel consumption, tire wear, travel time, etc.), comparing it to toll payment costs. In order to do so, three distinct sections were selected through the cluster analysis, so that there was at least one segment of the ANTT model of the first stage, a segment of the ANTT model of the second stage and a segment of the model of ARTESP. Vehicle operating costs were determined using the HDM-4 software and the economic analysis considered the Net Present Value (NPV), the Internal Rate of Return (IRR) and the Benefit/Cost Ratio (B/C). The alternatives considered in the analysis simulated the contractual requirements present in the CREMA program and in the ANTT Highway Exploration Program (HEP). The \"base\" condition for the analyzes simulated a limit scenario for intervention in the pavement, where it only occurred with very high roughness. After the simulations, it was concluded that the NPV method was the most appropriate for the analyzes, since all the stretches presented costs to users greater than the observed benefits. When performing complementary analysis, with even greater limits of roughness for the \"base\" condition, only the ANTT model of the second stage economically justified the concession, from the users point of view. It is concluded, therefore, that there is evidence that the road concessions in Brazil have not improved the condition of the pavements to the point of being economically justified, suggesting that the next concessions bring lower toll costs or present a greater number of works with significant impact on reducing travel time and increasing user safety.

O número de concessões rodoviárias tem aumentado em todo o mundo. Somente no Brasil, desde 1995, três etapas de concessão já foram realizadas pelo governo federal. No estado de São Paulo, as concessões estão em sua segunda etapa. Uma das principais justificativas para as concessões rodoviárias é a melhoria da condição dos pavimentos. Sendo assim, este trabalho buscou avaliar os benefícios oriundos da melhor conservação dos pavimentos, em termos da irregularidade longitudinal, diretamente relacionada com os custos de operação dos veículos (custos dos usuários: consumo de combustível, desgaste de pneus, tempo de viagem etc.), comparando com os custos por pagamento de pedágio. Para tanto, foram selecionados, através da análise de cluster, três trechos distintos, de tal forma que se tivesse, pelo menos, um segmento do modelo da ANTT da primeira etapa, um segmento do modelo da ANTT da segunda etapa e um segmento do modelo da ARTESP. Os custos de operação dos veículos foram determinados com uso do software HDM-4 e a análise econômica considerou o Valor Presente Líquido (VPL), a Taxa Interna de Retorno (TIR) e a Relação Benefício/Custo (B/C). As alternativas consideradas na análise simularam as exigências contratuais presentes no programa CREMA e no Programa de Exploração da Rodovia (PER) da ANTT. A condição \"base\" para as análises simulou um cenário limite para intervenção no pavimento, onde a mesma só ocorria com irregularidades muito elevadas. Após a realização das simulações, concluiu-se que o método do VPL era o mais adequado para as análises, pois todos os trechos apresentaram custos aos usuários maiores do que os benefícios observados. Ao se realizar análise complementar, com limites de irregularidade ainda maiores para a condição \"base\", somente o modelo da ANTT da segunda etapa justificou economicamente a concessão, do ponto de vista dos usuários. Conclui-se, portanto, que existem evidências de que as concessões rodoviárias no Brasil não têm melhorado a condição dos pavimentos a ponto de ser justificada economicamente, decorrendo a sugestão para que as próximas concessões acarretem custos de pedágio menores ou apresentem um maior número de obras com impacto significativo na redução do tempo de viagem e no aumento da segurança dos usuários. / The number of road concessions has increased worldwide. Only in Brazil, since 1995, three concession stages have already been carried out by the federal government. In the state of São Paulo, the concessions are in its second stage. One of the main justifications for road concessions is the improvement of pavement condition. Therefore, this study sought to evaluate the benefits of better pavement conservation in terms of longitudinal roughness, directly related to vehicle operating costs (user costs: fuel consumption, tire wear, travel time, etc.), comparing it to toll payment costs. In order to do so, three distinct sections were selected through the cluster analysis, so that there was at least one segment of the ANTT model of the first stage, a segment of the ANTT model of the second stage and a segment of the model of ARTESP. Vehicle operating costs were determined using the HDM-4 software and the economic analysis considered the Net Present Value (NPV), the Internal Rate of Return (IRR) and the Benefit/Cost Ratio (B/C). The alternatives considered in the analysis simulated the contractual requirements present in the CREMA program and in the ANTT Highway Exploration Program (HEP). The \"base\" condition for the analyzes simulated a limit scenario for intervention in the pavement, where it only occurred with very high roughness. After the simulations, it was concluded that the NPV method was the most appropriate for the analyzes, since all the stretches presented costs to users greater than the observed benefits. When performing complementary analysis, with even greater limits of roughness for the \"base\" condition, only the ANTT model of the second stage economically justified the concession, from the users point of view. It is concluded, therefore, that there is evidence that the road concessions in Brazil have not improved the condition of the pavements to the point of being economically justified, suggesting that the next concessions bring lower toll costs or present a greater number of works with significant impact on reducing travel time and increasing user safety.