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CHAPTER 1: BACKGROUND The objective of this project was to develop and test an analytical approach to prepare cost estimates for airport construction projects, both in the horizontal and vertical domains. The proposed cost estimating model is primarily intended for the capital planning phase, when uncertainty is high, but good cost estimates are necessary to optimize the use of scarce airport funding resources. This report describes the research process and findings of ACRP Project 01-19, âAirport Capital Improvements: Developing a Cost Estimating Model.â This work consisted of ten tasks, which were defined in the Amplified Work Plan prepared by the Research Team and reviewed by the ACRP 01-19 Project Panel: Task 1: Review and evaluate existing construction industry practices in developing and applying cost estimating models Task 2: Identify candidate airside and landside types for inclusion Task 3: Define and develop a framework for the model Task 4: Establish standard input/output format for database Task 5: Create a prototype model and database Task 6: Implement three representative case studies Task 7: Prepare interim report Task 8: Refine cost estimating model and populate database Task 9: Validate refined model Task 10: Prepare and submit Guidebook and Final Report 1
Problem statement Cost estimates for Airport Capital Improvement Plans (ACIPs) are prepared early in the stage of project planning, when design data available is limited and conceptual. The time frame for construction of the facility being estimated can vary from a few months to 20 years or more. At this point in the process, a simple rough order of magnitude estimate is usually the best that can be expected, due to the limited data available. Airport projects are often complex: âAirport projects have a whole series of special systems which are seen nowhere else, on an enormous scaleâ (Merkel and Cho, 2003). Two separate but related problems must be addressed: (1) improving the accuracy of the cost estimate as calculated from current and relevant cost data; and (2) improving the specificity of the project scope and unique conditions which must be entered into the model by the user. The problems are linked: The accuracy of the result is completely dependent upon the specificity of the scope. The dual challenges of providing sufficient accuracy and specific scoping vary in their characteristics, depending on the type of project. Some project types have greater potential for significant deviations, and therefore more potential for improvements. Another significant problem in cost modeling for the airport capital planning phase is the lack of standards. Combined with the frequent failure to employ accepted best practices for cost estimating, this results in large uncertainties and the inability to compare costs for projects across different airports, which may compete for the same source of limited capital funds. There is a need for a standardized cost model that allows for rapid development of cost estimates, incorporating best practices and a robust analytical methodology. 2
