Project Performance of Public-Private Partnership Projects Based on Various Contract Agreements and Correlation with Funding Mechanism

摘要

In the past, the state department of transportations (DOTs) used to build the highways and bridges through the traditional delivery method, design-bid-build (DBB). However, in the last couple of decades, alternative delivery methods, design-build (DB), and general contractor/construction management (GC/CM) were widely used in the construction of highways and bridges. These alternative delivery methods were employed when the state had a hundred percent funding available for the design and construction of the projects. Due to the scarcity of the public fund for highways and bridges, recently the public-private partnership (PPP) delivery method has been developed, so that the state can benefit from private funding to build the public projects. There are various types of PPP contract agreements, e.g., design-build-finance-operate-maintenance (DBFOM), design-build-finance-operate (DBFO), design-build-finance-maintenance (DBFM), and build-operate-transfer (BOT). Considering the recent use of different PPPs in highway and bridge projects, no study has been conducted to determine whether the type of PPP contract agreements has any effect on the cost and schedule performance of the projects. Therefore, this study has collected 10 PPP projects with two types of contract agreements, DBFOM and DBFM, to determine if there is any project performance difference in PPP projects. Through a data analysis, the results showed a slightly better cost performance and a significantly better schedule performance for DBFOM projects. Investigating funding and finance sources revealed the considerable difference in public funding and private finance between these two PPP agreements, which may be attributable to the difference found in cost and schedule performance. There have been some limitations in the number of projects, first due to the number of existing projects, and second, the available data to collect for the analysis. Similar to any new adoption, this limitation will be eliminated over time.