Understanding A + B Bidding Patterns and Policy Implications for ODOT Project Lettings. Final Report October 2013-September 2014.

摘要

The study aims to analyze data related to the performance of the A+B innovative contracting design that could help the Oklahoma Department of Transportation (ODOT) evaluate the costs and benefits of the design, leading to an assessment of current practices. A+B bidding is an innovative contracting design that allows contractors to propose an 'A' bid for cost and a 'B' bid for time. Since both cost and time matter in determining the winner, A+B bidding has the potential to reduce construction time while keeping the cost competitive. According to theory, as construction speeds up, cost goes up as well. So the net impact is unclear. In addition, the current practice of ODOT concerning the assignment of A+B bidding is primarily based on the size of projects and duration. Our goal is to identify any project related characteristics that could be added to the list to optimize the use of this innovative contract design as well as information on A+B practices across the states. This study has three objectives. The first objective is to provide detailed statistics on how A+B bidding is being utilized in ODOT lettings. We provide a summary of the characteristics of A+B bidding projects, the competition in these projects, and how they compare to the rest of the projects offered regularly at lettings. The second objective is to quantity the effect of A+B bidding on the low bids ODOT received, which represents the direct cost to the State. This is achieved with advanced techniques from the literature of program evaluation. This enables us to separate the observed difference in low bid caused by differences between projects themselves rather than the difference in bidding method, and provides an accurate estimate on the impact due to the adaptation of the special provision of A+B bidding. The last objective of the study is to dig one step deeper from the project level, and to analyze how individual construction items within an A+B bidding project respond to the pressure of time in terms of changes in itemized bids. Then we focus on items that demonstrate favorable responses, in other words their itemized bids are increased the least in A+B bidding compared to standard bidding, to look for projects which use such items to a considerable extent as desirable candidates for ODOT’s expansion of implementation of the A+B design in the future.