Showing papers in "Journal of Infrastructure Systems in 2011"

Transformation of Infrastructures: Sector Characteristics and Implications for Fundamental Change

Abstract: Infrastructure sectors such as energy or water supply, sanitation, or telecommunications provide us with services that are essential for modern life and for industrialized societies In this article, we explore some of the sectors’ key characteristics in order to better understand the conditions that stimulate or hinder far-reaching transformation processes in infrastructures It will be argued that durable and capital-intensive assets, together with a high degree of systemness generate considerable inertia and impede fundamental change At the same time, capital intensity and massive investment needs as well as negative environmental impacts represent sources for change A high degree of regulation and an often large share of public utilities also play a key role for sector dynamics Conceptual frameworks for studying infrastructures and making policy recommendations have to take into account these particularities and the close interplay of techno-economic, organizational, and institutional characteristics

Life-Cycle Assessment of Urban Water Provision: Tool and Case Study in California

Abstract: The exploration of life-cycle energy use and environmental effects from U.S. water infrastructure has been limited in spite of the strong connection between energy and water use. This research presents a methodology for quantifying the life-cycle energy consumption and associated air emissions from water supply, treatment, and distribution. A decision-support tool, the Water-Energy Sustainability Tool (WEST), has been developed to aid such analysis. WEST calculates the environmental effects of material production, including the supply chain, material delivery and transportation, construction and maintenance equipment use, energy production, and sludge disposal. Deterministic and probabilistic results for a California case study utility are provided to show the tool’s capabilities. Results indicate that producing a million liters of water consumes 5.4 GJ and produces 390 kg of CO2-equivalent greenhouse gases. Energy production is the most significant activity (50%), but material production, especially for ...

Postearthquake Recovery of a Water Distribution System: Discrete Event Simulation Using Colored Petri Nets

Abstract: Planning and preparedness is essential for any resilient infrastructure system. Modeling and simulation give engineers and planners a better understanding of the system and help them make better decisions. The objective of this study is to demonstrate an improved model for the disaster restoration process by using a discrete event simulation approach. The study also aims to help improve the postearthquake restoration process by simulating restoration curves. In this paper, colored Petri nets are used to model the system and to simulate its behavior. The resource allocation after a rare event such as an earthquake differs from the resource allocation of other projects and processes in that the time to do the repair and recovery is not known before the event, and the priorities might change for different operational plans and strategies. The trunk network of the Tokyo water distribution system was used as an example to present the scenario and to model the restoration process. The timed simulation allowed v...

Interface Network Models for Complex Urban Infrastructure Systems

Abstract: The reliability assessment of infrastructure systems providing power, natural gas, and potable water is an integral part of societal preparedness to unforeseen hazards. The topological properties of interface networks connecting electric substations to water pumping stations and natural gas compressors have received little attention, despite the key role these connections play in operation and failure propagation. This work introduces a performance assessment methodology for coupled infrastructures that links physical fragility modeling with the topology of realistic and ideal connecting interfaces. Distinct interfaces based on features such as betweenness, clustering, vertex degree, and Euclidean distance are assessed regarding their role in connecting utility systems and propagating failures from random and hurricane events in Harris County, Texas. The interface minimizing the Euclidean distance between electric substations and other utility nodes exhibits a slow performance decline as random failures increase, and retains the greatest functionality under hurricane events compared to alternative interfaces, although it suffers from limited efficiency and controllability during normal operation. A convenient hybrid interface using both betweenness and distance features shows adequate performance during normal operation while exhibiting tolerance to random failures and sufficient performance at increasing hurricane event levels. These findings provide utility owners and operators with new simple yet adequate strategies focused on the interface across complex systems to enhance routine operation and reduce the probability of widespread interdependent failures following disruptive events.

Critical Assessment Indicators for Measuring Benefits of Rural Infrastructure Investment in China

Abstract: Rural infrastructure is of vital importance for agricultural growth, economic development, and poverty alleviation, particularly in developing countries such as China. In line with the implementation of a Coordinated Urban-Rural Development Strategy, infrastructure investment in China has consciously been tilted to rural areas. An urgent need exists to assess whether the investment has induced the benefits as expected. Existing research on rural infrastructure investment assessment focuses primarily on economic return while neglecting its social and ecological benefits. This paper identifies a set of critical assessment indicators (CAIs) that can be used to evaluate the multifaceted benefits of rural infrastructure investment in China. Research data were collected through a questionnaire survey given to three groups of experts, including government officers, professionals, and business practitioners who are working in China’s housing and urban-rural development sector. Monte Carlo simulation (MCS) is used...

Costs and Benefits of IEQ Improvements in LEED Office Buildings

Abstract: Costs and benefits resulting from improved indoor environmental quality (IEQ) in Leadership in Energy and Environmental Design (LEED)-certified buildings are often hypothesized; however, the precise quantification of such costs and benefits remains a challenge. This research examined the incremental hard and soft costs of realizing IEQ improvements in LEED office buildings and related benefits to occupant well-being and productivity using a case study approach. Self-reported well-being and productivity data were collected by surveying employees occupying conventional offices compared to similar data upon their move to LEED offices. These pre- and postmove findings were analyzed using the life cycle cost analysis (LCCA) framework to calculate the potential economic gains of IEQ improvements to the organizations. The results indicate economically viable investments in LEED-IEQ credits and offers directions for future research. These preliminary findings may assist building owners/investors/policymakers in making better-informed building decisions towards IEQ improvements in buildings from the economic perspective of sustainability.

Bilevel Optimization for Integrated Shelter Location Analysis and Transportation Planning for Hurricane Events

Abstract: Responding to hurricanes is an exceedingly complex task, the effectiveness of which can significantly influence the final effects of a hurricane. Despite a lot of progress, recent events and unchecked population growth in hurricane-prone regions make it clear that many challenges remain. Hurricane Katrina has shown that having appropriate shelter options and an appropriate shelter evacuation plan are very important for hurricane evacuations. This paper proposes a scenario-based shelter location model for optimizing a set of shelter locations among potential alternatives that are robust across a range of hurricane events. This model considers the influence of changing the selection of shelter locations on driver route-choice behavior and the resulting traffic congestion. The state of North Carolina is used as a case study to show the applicability of the model.

Sewer performance reporting: Factors that influence blockages

Abstract: Managing sewer blockages represents a significant operational challenge for water utilities. In Australia, company-level blockage rates are used to compare the effectiveness of the management strategies of different utilities. Anecdotal evidence suggests that this basis may not be a fair one for comparison because blockages are influenced by a range of factors beyond management control and vary from company to company. This issue was investigated as part of a broader research effort on sewer-blockage management undertaken in conjunction with the Water Services Association of Australia (WSAA) and its members. A Web-based survey was used to collate expert opinion on factors that influence blockage rate. The identified factors were then investigated in an exploratory analysis of blockage-related data provided by two participating utilities, supported by literature reviews. The results indicate that blockage rate is influenced by a range of factors, including asset attributes, climatic conditions, water consumption, and soil type. Because these factors vary from utility to utility, this research supports the finding that company-level blockage rate in itself is not an appropriate metric for comparing management effectiveness.

Parametric model for conceptual cost estimation of concrete bridge foundations

Abstract: Motorway bridges constitute a major part of modern transportation infrastructure networks. Interestingly, although foundations substantially influence the bridge construction cost, few studies have focused on predesign cost estimates. This paper presents a conceptual cost-estimate model for bridge foundations that involves three stages: the selection of the foundation system, the estimation of the material quantities, and the estimation of the foundation cost. It describes an easy-to-use ground classification method, which combined with a rule-based system, leads to the choice of the foundation system. This paper also describes the development of prediction models for the material quantities of different types of foundations. The significant independent variables were identified by the experts in interview sessions. Despite its drawbacks, the stepwise regression methodology was applied to see whether the results are consistent with the experts’ opinion. The major assumptions underlying the correct application of the regression methodology were tested, and the necessary adjustments were made. The proposed conceptual cost-estimating methodology provides fast and reliable results that can be very useful in the early stages of a project.

Modeling Uncertainties in Emergency Service Resource Allocation

Abstract: The problem of allocating multiple emergency service resources to protect critical transportation infrastructures is studied in this paper. Different modeling approaches, including deterministic, stochastic programming, and robust optimization, are used to model various risk preferences in decision making under uncertain service availability and accessibility. Singapore is used as a case study for numerical experiments. The performances of different models are compared in terms of allocation strategies and the reliability and robustness of the system.

Reliability Evaluation of Corroding Pipelines Considering Multiple Failure Modes and Time-Dependent Internal Pressure

Abstract: A methodology is developed to evaluate the annual failure probabilities of a pressurized pipeline at an active metal-loss corrosion defect. The methodology takes into account three different failure modes at the defect (i.e., small leak, large leak, and rupture) and the time dependency of the pipe’s internal pressure by modeling the pressure as a simple stochastic process consisting of a sequence of independent and identically distributed random variables, each occupying a period of one year. The impact of periodic maintenance actions on the failure probabilities is incorporated in the methodology. Two numerical examples are used to illustrate the methodology. The sensitivity of the calculated failure probabilities with respect to the time dependency of the internal pressure is also investigated.

Exploratory State-Level Empirical Assessment of Pavement Performance

Abstract: This study uses aggregate state-level data from 1999 to 2006 in the United States to examine the relationships among pavement performance (pavement roughness) and preservation expenditure, dominant surface geology, and climate. To account for possible random variations in parameters across geographic locations and time periods, a random-parameters logit (mixed logit) model was used. The analysis was carried out separately for roads in different functional classifications and considered the effect that a variety of variables had on the proportion of pavements in each state that are in one of the four International Roughness Index categories (excellent, good, fair, poor) defined by the Federal Highway Administration. The results of the analysis showed the extent to which increased pavement preservation spending yields increased pavement performance and the nature of this relationship for different base pavement-performance conditions and different regions of climate and surface geology.

Framework for Computing a Performance Index for Urban Infrastructure Systems Using a Fuzzy Set Approach

Abstract: This paper presents a framework for characterizing, analyzing, and computing the performance of urban infrastructure systems. The framework is based on a systems approach and consists of performance indicators classified into three hierarchical levels: indicators, dimensions, and categories. A fuzzy synthetic evaluation technique has been developed to synthesize performance indicators into an index that ranges between 0 and 100. The performance of an individual infrastructure system, in the form of an index, is generated by aggregating the performance indicators in the first three hierarchical levels. The overall performance of the urban infrastructure systems is then obtained by combining the indexes of individual infrastructure systems. The relative importance of the performance indicators during the synthesis process is determined using the analytic hierarchy process technique. The framework demonstrates and measures the performance of the civil infrastructure systems in Kathmandu, Nepal. This framework can be applied to performance analysis of any infrastructure system in an urban area. It enables decision makers to identify the weak and strong components of urban infrastructure systems and to formulate appropriate strategies for infrastructure planning on the basis of performance and investment costs.

Dominance-Based Rough Set Approach to Budget Allocation in Highway Maintenance Activities

Abstract: This paper presents a decision-support system for the management of highway assets that uses a dominance-based rough set approach (DRSA). The decision concerns the allocation of maintenance funds among various highways owned by a central agency, and it takes into account multiple evaluation criteria. The proposed methodology supports the distribution of available resources to improve safety on highways, and it considers the current condition of each component of the highway infrastructure (pavements, bridges, signs, guardrails, culverts, and vegetation). The multiple-criteria decision problem in this paper is a sorting problem, i.e., the highways are assigned to preference-ordered classes, and the resources are allocated according to this sorting. The DRSA enables consideration of the quantitative and qualitative criteria, and it provides recommendations in terms of if-then decision rules, which are easily understandable by the decision maker. This approach enables an interaction between the analyst and the decision maker, and the decision maker’s preferences can be considered in the allocation of funds. This paper then presents an application of the proposed methodology to a case study performed for an Italian highway agency.

Supply-driven dynamic inoperability input-output price model for interdependent infrastructure systems

Abstract: A supply driven dynamic input-output inoperability model (SDIIM), which extends the classical dynamic inoperability input-output model (DIIM), is described in this paper. The classical DIIM was developed to help understand the infrastructure interdependencies of deliberate external attacks or unfortunate natural disasters, such as terrorist attacks or earthquakes and flooding. However, classical DIIM is a demand-driven model. More supply driven sectors exist than demand-driven sectors in interdependent infrastructure systems, but value-added perturbation is the predominant feature in supply driven sectors for an interrupt event. Moreover, compared to classical DIIM, the value added by the proposed SDIIM can be controlled more easily than the final demand of a disruptive event because the final demand perturbation may be affected by the psychological effect on consumers. A supply driven input-output inoperability model (IIM) has also been proposed to complement the classical IIM. However, the supply driven IIM is a static model, and only equilibrium values can be determined. The SDIIM presented in this paper has been formulated to model the behavior of the value-added input perturbation up to equilibrium and to characterize the required sector adjustments for achieving new levels of output values. In addition, the interdependency resilience coefficient and the interdependency index are discussed by using the SDIIM. In this paper, the large-scale snow disaster that occurred in south China in 2008 is used as a case study, in which the SDIIM is used to analyze the inoperability and dynamic output values recovery of sectors caused by a value-added disturbance. The SDIIM is shown to effectively compute interdependent inoperability and economic losses, which can provide valuable insights into risk assessment and the management of interdependent infrastructure systems and sectors of the economy.

Preliminary Comparative Life-Cycle Impacts of Streetlight Technology

Abstract: As part of a streetlight-retrofitting project in Pittsburgh, this study performed a cradle-to-grave life-cycle assessment of four lighting technologies: the widespread high-pressure sodium and metal halide lights, and the newer and more efficient induction and light-emitting-diode technologies. The study used a hybrid life-cycle-assessment approach to build life-cycle models for the various technologies, including manufacturing and installation data for process models and energy supply and input-output data to complete life-cycle models. Three different electricity scenarios were used to examine the sensitivity of the impacts to changes in energy supply: the United States average mix, the regional mix for the ReliabilityFirst Corporation region, and a scenario with 100% wind power. The results show that for all technologies, the impacts of electricity in the use phase dominates the results. Because of their lower wattage, light-emitting diode (LED) and induction technology perform favorably and similarly. With anticipated improvements in technology, however, LEDs are expected to be more efficient than induction in the near future and have lower environmental impacts by the time that Pittsburgh and other cities buy and install lights as part of these streetlight projects, which have the potential to show large cost and emissions savings.

Integrating WRc and CERIU Condition Assessment Models and Classification Protocols for Sewer Pipelines

Abstract: Adoption of a suitable sewer pipeline condition classification protocol is recognized as an indispensable first step in worldwide sewer rehabilitation industry. Various condition classification sys...

Guidance for cost-effective selection of pavement marking materials for work zones

Abstract: Pavement markings provide important information to motorists, especially in a work zone environment where alignments are often changed from what is typical. Unlike normal roadway applications, work zone pavement markings are often placed on the roadway for a limited period of time, such as during an interim phase of construction. The performance and total cost for each material may vary greatly depending on a number of factors, such as traffic volume, surface type, and project duration. The objective of this study is to develop a systematic approach to provide practitioners with objective guidance for selecting cost-effective pavement marking materials for work zones that meet specific performance requirements. A Monte Carlo simulation and sensitivity analyses were conducted to establish a cost-based decision support guidance given a set of factors influencing the performance of marking materials. Four types of materials considered in this study were paint, thermoplastics, temporary tapes, and traffic buttons. The analysis results indicated that traffic buttons perform slightly better at shorter phase durations and moderate traffic levels on the concrete surface. The use of thermoplastics was recommended as the lowest-cost alternative only on the asphalt surface with moderate project durations and traffic levels. Paint markings are recommended for short-duration projects regardless of traffic conditions or pavement surfaces. DOI: 10.1061/(ASCE)IS.1943-555X.0000043. © 2011 American Society of Civil Engineers. CE Database subject headings: Monte Carlo method; Workspace; Service life; Pavement markings; Economic factors; Costs. Author keywords: Pavement markings; Marking materials; Monte Carlo simulation; Work zone; Service life; Economic analysis.

Self-Financing and Distance-Based Highway Pricing Scheme: State Highway System Perspective

Abstract: A distance-based highway pricing scheme has been considered a means to tackle highway revenue shortfalls as an alternative to the current taxation on motor fuels. To establish fee rates for a distance-based pricing scheme, this study argues that maintenance and management of the highway system be self-financed by its users, who are responsible for maintenance, repair, and rehabilitation of the highway system. Each user’s highway cost responsibility is determined by its vehicle class, road functional class, types and frequency of interventions, and other technical parameters. This paper uses the State Highway Cost Allocation Study (HCAS) tool to analyze expenditures, revenues, and usages of a state highway system to obtain cost borne by various user groups. On the basis of Indiana State Highway data, cost responsibility of each highway user varies between 0.66¢/km and 25.05¢/km among 20-vehicle types. Sensitivity analysis was carried out considering several technical parameters including load equivalency factor, non-load-related impacts on pavement, and minimum requirements for construction and rehabilitation to reveal the reasonable ranges of cost responsibility of different users.

Cost Structure and Efficiency of Korea’s Road and Rail in the Manufacturing Industries

Abstract: This paper analyzes the contribution of public infrastructure to private sector. It takes the example of road and rail and investigates their impact on South Korean manufacturing industries. To assess the cost structure and efficiency of investments in infrastructure, economies of scale, effects of infrastructure on variable cost and output, investment condition for infrastructure, and substitution and price elasticities are calculated. The divergence of infrastructure stocks from their static equilibrium levels influences production efficiency. Overall, investments in road and rail have positive effects on the manufacturing industries in Korea. This study expands the scope of existing studies by decomposing the internal rate of return (IRR) and the present value of benefit (BPV) into variable cost reduction, investment cost reduction, and rent. It was found that BPV checks only the magnitude of benefit, whereas IRR indicates the existence of efficiency by investigating total cost reduction and rent. Fina...

Cost Functions for Australia's Railways

Abstract: This paper utilizes a unique data set comprising almost hundred years of Australian railway history and applies the translog and symmetric generalized McFadden functional forms to the data in order to estimate cost functions for Australia’s seven state-owned railway systems. It discusses the advantages and disadvantages of each functional form in light of the data, finding the translog to be superior, and the shortcomings of the data. It also explores economies of scale and density and suggests a simple method to calculate long-run marginal cost, which may be of use in applications such as economic regulation.