Item-level quantity-based preliminary cost estimating system for highway earthwork, landscape, subgrade treatments, base, surface courses, pavement and traffic control
The primary purpose of this research is to develop systematic procedures, quantity models and an automated computing tool for highway estimating process for the Texas Department of Transportation (TxDOT). This study built a preliminary cost estimating system that toggles between project input information, predictive item-level quantity models, and segregated unit prices for highway work items. A computer application and a prototype web-based system both using relational databases were developed. The design concept of this automated system is to better exploit work item historical unit prices and initiate preliminary estimates with quantity-based models for later periodic quantity adjustment. This approach was chosen because of conventional approach lacking of quantity information until 90% to 95% design complete. This cost estimating system enables continuity of item-level quantity tracking as projects evolve to later phases. The output, in the form of a report can be uploaded to the TxDOT Design and Construction Information System for subsequent cost control and management.