Editor’s Note

“State-of-Practice Technologies on Accelerated Urban Highway Rehabilitation: I-15 California Experience.” Authors Lee and Thomas present an innovative fast-track approach applied to a heavily trafficked urban freeway reconstruction project in Southern California. The operations, estimated to take $10\text{months}$ using traditional nighttime closures, were completed in two $9\text{-}\text{day}$ continuous closures with round-the-clock operations. The estimated benefits of the accelerated reconstruction include a 28% reduction in agency cost and a 29% time value savings to road users compared to the traditional approach of using repeated nighttime closures.

“Decision Support System to Evaluate and Compare Concession Options.” The increased popularity of concession projects over the last 2 decades has created a need for a decision support system capable of evaluating and comparing several concession project investment options in an effective and efficient manner. McCowan and Mohamed present a system which takes into consideration both financial and nonfinancial aspects of the investment option as well as the uncertainties commonly encountered during the feasibility stage of a project. The authors outline and validate the system’s design and structure by applying it to three real-life case studies.

“Float Consumption Impact on Cost and Schedule in the Construction Industry.” Float loss impact in noncritical activities is one of the complicated delays to assess on a project’s duration and cost. Sakka and El-Sayegh present a method to control the risks associated with float loss in construction projects. The method uses an analysis technique that combines the results of cost range estimates and stochastic scheduling, quantifying the float loss impact on project duration and cost.

“Schedule Analysis under the Effect of Resource Allocation.” Ibbs and Nguyen present research which shows that the analysis of delays without using resource allocation, the more commonly-used method, substantially affects the accuracy of the results of the analysis. Practical and necessary steps are proposed to enhance the existing window analysis technique. A case study is also presented to compare the enhanced window analysis with the existing analysis.

“Residential Building Projects: Building Cost Indicators and Drivers.” Early cost estimates in Germany rely on multiplying a cost indicator with the gross floor area. However, currently, the identification of the cost indicator is not accurately practiced. Authors Stoy and Schalcher present relevant cost drivers for estimating residential properties’ costs in German-speaking regions, identifying them using regression analysis. These four indicated drivers show which parameters are the determinants for the selection of project-specific cost indicators.

“Teaching Evaluations for Construction Engineering and Management: Opportunity to Move Us Forward.” Recently, there has been a call for systematic modifications in research universities to clear the path for cross-disciplinary research communities. In this context, Bernold investigates the effect of student ratings used to measure teaching effectiveness. A student rating form is presented to align teaching objectives, learning outcomes, and the criteria for evaluating teaching. The form is based on the most up-to-date understanding of effective teaching, the new ABET criteria, and a view of the future of the construction profession.

“Interorganizational Teamwork in the Construction Industry.” Interorganizational teamwork has attracted considerable attention lately and is one of the important characteristics of the construction industry. Building on a modified model, Fong and Lung investigate the effects of cultural and contextual factors and employee attitudes on team orientation. Using correlation and multiple regression analyses, the findings indicate that there are positive relationships between team orientation and contractual trust, competence trust and tank interdependence, and a negative relationship between team orientation and opportunism.

“Decision Making in Flexible Mine Production System Design Using Real Options.” Having the ability to plan for uncertainties associated with project risks and opportunities is increasingly recognized as critical to long-term corporate success. By engaging in planning for flexible production systems, the effects of risk on a particular project value can be examined, project volatility can be calculated, and potential flexible alternatives can be evaluated. Mayer and Kazakidis demonstrate that flexibility can become an equal partner among the parameters controlling the decision-making process. The authors present a methodology in production system design by introducing flexibility into design through the application of real options valuation techniques.

“Fuzzy Optimization Model for Earthwork Allocations with Imprecise Parameters.” Existing linear programming models of earthwork allocations in roadway construction assume that unit cost coefficients of earthwork activities are certain and deterministic numbers. Karimi, Mousavi, Kaveh, and Afshar present a fuzzy linear programming model of earthwork allocations based on the assumptions of unit cost coefficients and borrow pits/disposal sites capacities as fuzzy numbers. The model also minimizes total earthmoving cost as an objective function. It is then demonstrated that the proposed method, compared to a deterministic method, introduces a more robust solution as the result of giving fuzziness to uncertain parameters.

“Delay Time Analysis in Microtunneling Projects.” Delay in microtunneling projects is a complex multivariate problem. Delay data, including delay duration, delay reason, time, and location from the start to the stopping point, are collected from 35 microtunneling projects. Authors Hegab and Smith select a predictive model using a probabilistic approach to represent the delay time. In addition, based on data characteristics, a Weibull distribution is determined to best represent the overall delay duration in microtunneling projects.