992 resultados para road projects
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Mode of access: Internet.
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Mode of access: Internet.
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Performance-based maintenance contracts differ significantly from material and method-based contracts that have been traditionally used to maintain roads. Road agencies around the world have moved towards a performance-based contract approach because it offers several advantages like cost saving, better budgeting certainty, better customer satisfaction with better road services and conditions. Payments for the maintenance of road are explicitly linked to the contractor successfully meeting certain clearly defined minimum performance indicators in these contracts. Quantitative evaluation of the cost of performance-based contracts has several difficulties due to the complexity of the pavement deterioration process. Based on a probabilistic analysis of failures of achieving multiple performance criteria over the length of the contract period, an effort has been made to develop a model that is capable of estimating the cost of these performance-based contracts. One of the essential functions of such model is to predict performance of the pavement as accurately as possible. Prediction of future degradation of pavement is done using Markov Chain Process, which requires estimating transition probabilities from previous deterioration rate for similar pavements. Transition probabilities were derived using historical pavement condition rating data, both for predicting pavement deterioration when there is no maintenance, and for predicting pavement improvement when maintenance activities are performed. A methodological framework has been developed to estimate the cost of maintaining road based on multiple performance criteria such as crack, rut and, roughness. The application of the developed model has been demonstrated via a real case study of Miami Dade Expressways (MDX) using pavement condition rating data from Florida Department of Transportation (FDOT) for a typical performance-based asphalt pavement maintenance contract. Results indicated that the pavement performance model developed could predict the pavement deterioration quite accurately. Sensitivity analysis performed shows that the model is very responsive to even slight changes in pavement deterioration rate and performance constraints. It is expected that the use of this model will assist the highway agencies and contractors in arriving at a fair contract value for executing long term performance-based pavement maintenance works.
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Performance-based maintenance contracts differ significantly from material and method-based contracts that have been traditionally used to maintain roads. Road agencies around the world have moved towards a performance-based contract approach because it offers several advantages like cost saving, better budgeting certainty, better customer satisfaction with better road services and conditions. Payments for the maintenance of road are explicitly linked to the contractor successfully meeting certain clearly defined minimum performance indicators in these contracts. Quantitative evaluation of the cost of performance-based contracts has several difficulties due to the complexity of the pavement deterioration process. Based on a probabilistic analysis of failures of achieving multiple performance criteria over the length of the contract period, an effort has been made to develop a model that is capable of estimating the cost of these performance-based contracts. One of the essential functions of such model is to predict performance of the pavement as accurately as possible. Prediction of future degradation of pavement is done using Markov Chain Process, which requires estimating transition probabilities from previous deterioration rate for similar pavements. Transition probabilities were derived using historical pavement condition rating data, both for predicting pavement deterioration when there is no maintenance, and for predicting pavement improvement when maintenance activities are performed. A methodological framework has been developed to estimate the cost of maintaining road based on multiple performance criteria such as crack, rut and, roughness. The application of the developed model has been demonstrated via a real case study of Miami Dade Expressways (MDX) using pavement condition rating data from Florida Department of Transportation (FDOT) for a typical performance-based asphalt pavement maintenance contract. Results indicated that the pavement performance model developed could predict the pavement deterioration quite accurately. Sensitivity analysis performed shows that the model is very responsive to even slight changes in pavement deterioration rate and performance constraints. It is expected that the use of this model will assist the highway agencies and contractors in arriving at a fair contract value for executing long term performance-based pavement maintenance works.
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This paper describes a methodology of using individual engineering undergraduate student projects as a means of effectively and efficiently developing new Design-Build-Test (DBT) learning experiences and challenges.
A key aspect of the rationale for this approach is that it benefits all parties. The student undertaking the individual project gets an authentic experience of producing a functional artefact, which has been the result of a design process that addresses conception, design, implementation and operation. The supervising faculty member benefits from live prototyping of new curriculum content and resources with a student who is at a similar level of knowledge and experience as the intended end users of the DBT outputs. The multiple students who ultimately undertake the DBT experiences / challenges benefit from the enhanced nature of a learning experience which has been “road tested” and optimised.
To demonstrate the methodology the paper will describe a case study example of an individual project completed in 2015. This resulted in a DBT design challenge with a theme of designing a catapult for throwing table tennis balls, the device being made from components laser cut from medium density fibreboard (MDF). Further three different modes of operation will be described which use the same resource materials but operate over different timescales and with different learning outcomes, from an icebreaker exercise focused on developing team dynamics through to full DBT where students get an opportunity to experience the full impact of their design decisions by competing against other students with a catapult they have designed and built themselves.
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The 2015 Corridor Management Plan for the Iowa Great River Road is modeled after similar plans for other National Scenic Byways: it is a dynamic, written document that describes the broad range of goals, objectives, policies, programs, projects and activities which can assist with protecting the intrinsic resources of a byway; interpreting the engaging stories of the byway; and promoting and presenting the byway with services and amenities to meet the needs and expectations of the traveling public.
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A key component of Iowa’s transportation system is the public roadway system owned and maintained by the state, cities and counties. In order to regularly evaluate the conditions of Iowa’s public roadway infrastructure and assess the ability of existing revenues to meet the needs of the system, the Iowa Department of Transportation’s 2006 Road Use Tax Fund (RUTF) report to the legislature included a recommendation that a study be conducted every five years. That recommendation was included in legislation adopted in 2007 and signed into law. The law specifically requires the following (2016 Iowa Code Section 307.31): “The department shall periodically review the current revenue levels of the road use tax fund and the sufficiency of those revenues for the projected construction and maintenance needs of city, county, and state governments in the future. The department shall submit a written report to the general assembly regarding its findings by December 31 every five years, beginning in 2011. The report may include recommendations concerning funding levels needed to support the future mobility and accessibility for users of Iowa's public road system.” “The department shall evaluate alternative funding sources for road maintenance and construction and report to the general assembly at least every five years on the advantages and disadvantages and the viability of alternative funding mechanisms.” To comply with this requirement, the Iowa Department of Transportation (DOT) prepared a 2011 RUTF Study (www.iowadot.gov/pdf_files/RUTFStudy2011.pdf). This study relied heavily on the work of the Governor’s Transportation 2020 Citizen Advisory Commission (CAC), established by Governor Terry E. Branstad to assist the Iowa DOT as it assessed the condition of Iowa’s roadway system and evaluated current and future funding available to best address system needs. The 2011 RUTF Study ultimately led to the passage of Senate File 257 in the 2015 legislative session that was signed into law on February 25, 2015. The major component of this bill was the increase of the state fuel tax rate on March 1, 2015, in order to meet the critical need funding shortfall identified in the study. With the recent increase in the state fuel tax rate, jurisdictions across Iowa are now putting those additional funds into road and bridge construction projects. With one full construction season complete following the increase in funding, it is difficult to accurately assess the long-term impact on construction needs. Therefore, this 2016 RUTF Study focuses on the actions taken since the 2011 RUTF Study and on alternative funding mechanisms.
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Even though today’s corporations recognize that they need to understand modern project management techniques (Schwalbe, 2002, p2), many researchers continue to provide evidence of poor IT project success. With Kotnour, (2000) finding that project performance is positively associated with project knowledge, a better understanding of how to effectively manage knowledge in IT projects should have considerable practical significance for increasing the chances of project success. Using a combined qualitative/quantitative method of data collection in multiple case studies spanning four continents, and comprising a variety of organizational types, the focus of this current research centered on the question of why individuals working within IT project teams might be motivated towards, or inhibited from, sharing their knowledge and experience in their activities, procedures, and processes. The research concluded with the development of a new theoretical model of knowledge sharing behavior, ‘The Alignment Model of Motivational Focus’. This model suggests that an individual’s propensity to share knowledge and experience is a function of perceived personal benefits and costs associated with the activity, balanced against the individual’s alignment to a group of ‘institutional’ factors. These factors are identified as alignments to the project team, to the organization, and dependent on the circumstances, to either the professional discipline or community of practice, to which the individual belongs.