Design Cost Analysis of Transportation Projects

Transportation projects are usually designed in three phases: phase I is the preliminary design report, phase II involves the preparation of the actual construction documents including plans and specifications, and phase III involves the construction inspection and contract administration of the project. The process of arriving at total design man-hours and the related design costs is often the most contentious and difficult part of phase II for both the consultant and the STA (State Transportation Agency). The main objective of this research is to model the design costs of consultant designed projects. Actual data were collected from The Illinois Department of Transportation (IDOT). Statistical modeling techniques were used to predict the design costs. The models developed in the following pages will help supplement the current methods of estimating design costs currently used by IDOT. Currently the Illinois Department of Transportation maintains a set of manuals used by the Bureau of Design and Environment for guiding engineers through the design phase for highway projects. These manuals are very comprehensive covering all facets of the design process. The models contained in this research could be implemented in the Design and Environment manuals.