Optimal policies for greenhouse gas emission minimization under multiple agency budget constraints in pavement management

Greenhouse gas emissions reduction has garnered special importance in recent times in the transportation sector, including pavement design and management. In this study, we incorporate this environmental objective in pavement management. We present an optimization problem to minimize GHG emissions under multiple budget constraints by determining joint management strategies for a range of heterogeneous interventions, including maintenance, rehabilitation and reconstruction. We propose a computationally efficient bottom-up solution algorithm, which is built on Lagrangian Relaxation and Dynamic Programming. Finally, we apply our findings to a real-world highway network in California, where the results show a potential GHG emissions reduction of 20% through an increased combined budget of 35% on the Pareto frontier

An integrated network-level management model for maintenance of flexible pavements

Poslednjih godina, preduzeća koja se bave održavanjem putne infrastrukture, na državnom i lokalnom nivou, se suočavaju sa novim zahtevima kada je reč o održavanju puteva. Pored potrebe da se smanje ukupni troškovi održavanja putne mreže i usklade sa realnim mogućnostima i raspoloživim budžetom, i da se u isto vreme obezbedi održavanje putne mreže u odgovarajućem i stabilnom stanju, preduzeća koja upravljaju putnom infrastrukturom se nalaze pred još zahtevnijim izazovom, a to je uključivanje klimatskih promena i uticaja na životnu sredinu u proces odlučivanja...In recent years, road agencies and authorities, responsible for maintaining road networks on a national level, are being faced with new challenges. In addition to their attempt to keep overall maintenance costs low while keeping their road networks in an appropriate condition, road agencies are facing even more demanding challenges as they become obliged to incorporate effects of global climate change and other environmental and social impacts into their decision making process..

Интегрисани модел управљања одржавањем фл[е]!ксибилних коловоза на нивоу меже

Последњих година, предузећа која се баве одржавањем путне инфраструктуре, на државном и локалном нивоу, се суочавају са новим захтевима када је реч о одржавању путева. Поред потребе да се смање укупни трошкови одржавања путне мреже и ускладе са реалним могућностима и расположивим буџетом, и да се у исто време обезбеди одржавање путне мреже у одговарајућем и стабилном стању, предузећа која управљају путном инфраструктуром се налазе пред још захтевнијим изазовом, а то је укључивање климатских промена и утицаја на животну средину у процес одлучивања...In recent years, road agencies and authorities, responsible for maintaining road networks on a national level, are being faced with new challenges. In addition to their attempt to keep overall maintenance costs low while keeping their road networks in an appropriate condition, road agencies are facing even more demanding challenges as they become obliged to incorporate effects of global climate change and other environmental and social impacts into their decision making process..

Flexible pavements and climate change: impact of climate change on the performance, maintenance, and life-cycle costs of flexible pavements

Flexible pavements are environmentally sensitive elements of infrastructure and their performance can be influenced by climate. Climate change poses a challenge to design and management of flexible pavements in the future. Climate change can occur worldwide and thus all flexible pavements can be exposed to the impact. However, an assessment framework is not available to evaluate the impact of climate change on flexible pavements in terms of performance, maintenance decision-making and the subsequent life-cycle costs (LCC). This research has attempted to develop such a framework. Case studies on six flexible pavement sections from the United States were performed to demonstrate the application of the framework. The framework started with the investigation of climate change using IPCC’s (Inter-governmental Panel on Climate Change) climate change projections. Combinations of climate change projections and local historical climate were adopted as climatic inputs for the prediction of pavement performance. The Mechanistic-Empirical Pavement Design Guide (MEPDG) was used for prediction of pavement performance because it can provide reliable performance predictions with consideration of climatic factors. Pavement performance predictions were applied to schedule maintenance interventions. Maintenance effects of treatments were considered in maintenance decision-making. Maintenance effect models of International Roughness Index (IRI) and rutting were validated using pavement condition survey data from Virginia. With selected climate related LCC components, three maintenance interventions were optimised using a genetic algorithm to achieve the minimum LCC. Eventually the outputs of the system including pavement performance, intervention strategies, and LCC can be compared under various climate change and baseline scenarios. Hence, the differences in performance, decision-making, and LCC due to climate change can be derived. The conclusions were drawn based on the scheme of maintenance decision-making. If flexible pavements are not maintained (Alternative 0), an increase in LCC will be incurred by climate change due to an increase in road roughness (IRI). For pavements maintained with strict thresholds (Alternative 1), climate change may lead to a significant reduction in the service life when the maintenance is triggered by climate sensitive distress. However, benefit can be gained from decreasing LCC as the earlier triggered maintenance may result in less average IRI. As a consequence, user costs, which can be associated with IRI, can be reduced. Hence, LCC can be reduced as user costs usually dominate LCC. However, the net present value (NPV) of agency costs can be increased due to the early intervention. For pavements with optimised maintenance (Alternative 2), the LCC is almost unaffected by climate change. However, the type or application time of interventions may need to be changed in order to achieve this. Furthermore, the balance between agency and user costs did not seem to be influenced by climate change for Alternative 2. Agencies should be aware that maintenance optimisation can significantly reduce the LCC and make the best use of treatments to mitigate the effects of climate change on flexible pavements. Pavement maintained with strict triggers may require earlier interventions as a result of climate change but can gain benefit in LCC. However, this indicates that a responsive maintenance regime may not take full advantage of interventions and that maintenance could be planned to be performed earlier in order to achieve minimised LCC. Due to climate change, road users may spend more on fuels, lubricants and tyre wear on flexible pavement sections that do not receive any maintenance treatments

Flexible pavements and climate change: impact of climate change on the performance, maintenance, and life-cycle costs of flexible pavements

Flexible pavements are environmentally sensitive elements of infrastructure and their performance can be influenced by climate. Climate change poses a challenge to design and management of flexible pavements in the future. Climate change can occur worldwide and thus all flexible pavements can be exposed to the impact. However, an assessment framework is not available to evaluate the impact of climate change on flexible pavements in terms of performance, maintenance decision-making and the subsequent life-cycle costs (LCC). This research has attempted to develop such a framework. Case studies on six flexible pavement sections from the United States were performed to demonstrate the application of the framework. The framework started with the investigation of climate change using IPCC’s (Inter-governmental Panel on Climate Change) climate change projections. Combinations of climate change projections and local historical climate were adopted as climatic inputs for the prediction of pavement performance. The Mechanistic-Empirical Pavement Design Guide (MEPDG) was used for prediction of pavement performance because it can provide reliable performance predictions with consideration of climatic factors. Pavement performance predictions were applied to schedule maintenance interventions. Maintenance effects of treatments were considered in maintenance decision-making. Maintenance effect models of International Roughness Index (IRI) and rutting were validated using pavement condition survey data from Virginia. With selected climate related LCC components, three maintenance interventions were optimised using a genetic algorithm to achieve the minimum LCC. Eventually the outputs of the system including pavement performance, intervention strategies, and LCC can be compared under various climate change and baseline scenarios. Hence, the differences in performance, decision-making, and LCC due to climate change can be derived. The conclusions were drawn based on the scheme of maintenance decision-making. If flexible pavements are not maintained (Alternative 0), an increase in LCC will be incurred by climate change due to an increase in road roughness (IRI). For pavements maintained with strict thresholds (Alternative 1), climate change may lead to a significant reduction in the service life when the maintenance is triggered by climate sensitive distress. However, benefit can be gained from decreasing LCC as the earlier triggered maintenance may result in less average IRI. As a consequence, user costs, which can be associated with IRI, can be reduced. Hence, LCC can be reduced as user costs usually dominate LCC. However, the net present value (NPV) of agency costs can be increased due to the early intervention. For pavements with optimised maintenance (Alternative 2), the LCC is almost unaffected by climate change. However, the type or application time of interventions may need to be changed in order to achieve this. Furthermore, the balance between agency and user costs did not seem to be influenced by climate change for Alternative 2. Agencies should be aware that maintenance optimisation can significantly reduce the LCC and make the best use of treatments to mitigate the effects of climate change on flexible pavements. Pavement maintained with strict triggers may require earlier interventions as a result of climate change but can gain benefit in LCC. However, this indicates that a responsive maintenance regime may not take full advantage of interventions and that maintenance could be planned to be performed earlier in order to achieve minimised LCC. Due to climate change, road users may spend more on fuels, lubricants and tyre wear on flexible pavement sections that do not receive any maintenance treatments