The Design-Build procurement method for transportation is proving to have distinct advantages for certain transportation projects. The use of Design-Build is gaining popularity with many owners. The final Engineer's Estimate is crucial to the determination that a contractor's Design-Build Price Proposal is acceptable to the owner. As such, it is important that traditional cost estimating techniques be refined to accommodate the numerous unknowns and risk assessment strategies that accompany Design-Build contracts. In most Design-Build projects, very little design, if any, is complete prior to awarding a contract. In some states a traditional design-bid-build approach is attempted. In other states, a true programmatic estimate is used as the final Engineer's Estimate. However, with the former approach, a "best-guess" approach must be made as to quantities, labor, and contingencies when many of these details are unavailable to the estimator. With the latter approach, the programmatic estimate may not capture all of the subtleties surrounding the project. A more scientific and consistent method of determining the final Engineer's Estimate is needed.

This project will expand on the efforts presented in the recently released ¿Design-Build Effectiveness Study¿ prepared for the FHWA by focussing on the procedures used for cost estimating Design-Build projects. This project will provide a synthesis of current practices for determining the Engineers' Estimates for Design-Build projects in use across the country. The project will highlight best practices and formulate the most appropriate method for cost estimating on Design-Build Projects.

The project will first provide a synthesis of current practices for Design-Build Engineer¿s Estimates. It is intended that this task will result in an interim report deliverable. The next task will be to gage those ¿best practices¿ which render consistent results and provide the owner with understandable and reliable cost estimates. This will include an examination of each owner¿s ¿success rate¿ in adequately predicting the cost of the awarded Design-Build projects using their current cost estimating techniques. An added focus will be on the estimation of quantities, risk assessment, contingencies, and the effect of third party constraints (permitting, utility coordination, right-of-way acquisition, etc.) on the Engineer¿s Estimate. Recommendations will be provided as to an approach that is not excessively cumbersome, yet encompasses the subtleties of each project. The final deliverable will include the synthesis, best practices report, and recommendations for Design-Build cost estimating procedures. The recommendation of an acceptable variation between the Engineer¿s Estimate and the successful bidder¿s Price Proposal will also be targeted through statistical analyses or other such methods.

Our target is to have 10 ¿15 agencies participate at a rate of $15,000 - $20,000 per agency for the one year study.