A Methodological Framework for Modeling Pavement Maintenance Costs for Projects with Performance-based Contracts

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.

Privity of Contract and Third Party Rights in European Construction Projects

Privity of contract has lately been criticized in several European jurisdictions, particu-larly due to the onerous consequences it gives rise to in arrangements typical for the modern exchange such as chains of contracts. Privity of contract is a classical premise of contract law, which prohibits a third party to acquire or enforce rights under a contract to which he is not a party. Such a premise is usually seen to be manifested in the doctrine of privity of contract developed under common law, however, the jurisdictions of continental Europe do recognize a corresponding starting point in contract law. One of the traditional industry sectors affected by this premise is the construction industry. A typical large construction project includes a contractual chain comprised of an employer, a main contractor and a subcontractor. The employer is usually dependent on the subcontractor's performance, however, no contractual nexus exists between the two. Accordingly, the employer might want to circumvent the privity of contract in order to reach the subcontractor and to mitigate any risks imposed by such a chain of contracts. From this starting point, the study endeavors to examine the concept of privity of con-tract in European jurisdictions and particularly the methods used to circumvent the rule in the construction industry practice. For this purpose, the study employs both a com-parative and a legal dogmatic method. The principal aim is to discover general principles not just from a theoretical perspective, but from a practical angle as well. Consequently, a considerable amount of legal praxis as well as international industry forms have been used as references. The most important include inter alia the model forms produced by FIDIC as well as Olli Norros' doctoral thesis "Vastuu sopimusketjussa". According to the conclusions of this study, the four principal ways to circumvent privity of contract in European construction projects include liability in a chain of contracts, collateral contracts, assignment of rights as well as security instruments. The contempo-rary European jurisdictions recognize these concepts and the references suggest that they are an integral part of the current market practice. Despite the fact that such means of circumventing privity of contract raise a number of legal questions and affect the risk position of particularly a subcontractor considerably, it seems that the impairment of the premise of privity of contract is an increasing trend in the construction industry.

Evaluating Methods of Calculating the Fixed Fee on Professional Service Contracts

The South Carolina Department of Transportation routinely retains Professional Consulting Engineering firms to provide engineering design and related professional services for the preparation of construction plans or design-build Request for Proposal bid packages for a wide variety of Federal-aid Highway Program roadway and bridge construction projects throughout South Carolina.The purpose of this project is to examine the current process of determining a "Fair and Reasonable" fixed fee for professional service contracts and to evaluate possible alternative methods including practices in other states that may improve the process, particularly in light of the considerable variation in audited overhead rates among consulting firms. In reviewing such alternative methods particular attention will be given to evaluating the potential impact of the method as an incentive to consulting firms to effectively manage their overhead costs.

The role of microcomputer-based laboratory display in supporting the construction of new understanding in kinematics

Teachers' failure to utilise MBL activities more widely may be due to not recognising their capacity to transform the nature of laboratory activities to be more consistent with contemporary constructivist theories of learning. This research aimed to increase understanding of how MBL activities specifically designed to be consistent with a constructivist theory of learning support or constrain student construction of understanding. The first author conducted the research with his Year 11 physics class of 29 students. Dyads completed nine tasks relating to kinematics using a Predict-Observe-Explain format. Data sources included video and audio recordings of students and teacher during four 70-minute sessions, students' display graphs and written notes, semi-structured student interviews, and the teacher's journal. The study identifies the actors and describes the patterns of interactions in the MBL. Analysis of students' discourse and actions identified many instances where students' initial understanding of kinematics were mediated in multiple ways. Students invented numerous techniques for manipulating data in the service of their emerging understanding. The findings are presented as eight assertions. Recommendations are made for developing pedagogical strategies incorporating MBL activities which will likely catalyse student construction of understanding.