摘要: |
To promote accelerated project delivery, a number of state transportation agencies (STAs) have utilized alternative contracting methods (ACMs). Common concerns STAs have with implementation of these methods are their effectiveness in delivering projects faster and their impact on other important project performance measures such as cost, quality, and safety. The goals of this study were to summarize the state of practice of selecting ACMs that can accelerate project completion and to identify driving factors for selecting one method over another. In this study, accelerated project completion was defined as earlier completion date through faster construction, expedited project development, shorter duration of project closeout, or a combination of these. The study methodology included three sequential efforts. The first effort was selection of methods typically implemented to accelerate project completion. Initially, 17 methods were identified from the Primer on Contracting for the Twenty-first Century, prepared by AASHTOs Subcommittee on Construction. Next was a comprehensive review of the current literature regarding ACMs, focusing on the 17 methods and their potential to reduce schedule duration. Finally, a website-based electronic survey including quantitative and qualitative questions was developed and sent to the members of the AASHTO Subcommittee on Construction in all 50 states, the District of Columbia, and Puerto Rico. Thirty agencies responded to the survey. Among the 17 ACMs addressed in the survey, two methods were not identified as being used, and three new methods were added by STAs. Based on an assessment of the advantages, critical selection factors, and potential for schedule reduction, five ACMs show the highest potential for accelerating project completion. These methods are listed here in order of highest relative potential: Designbuild, Incentives and disincentives, Cost-plus-time bidding, Interim completion dates, and No-excuse incentives. From the perspective of survey respondents, the selection of these methods is driven primarily by the requirement to meet a critical completion date. All five methods reduce schedule duration, and three reduce duration more than 10% of the planned value (cost-plus-time incentive/disincentive and designbuild). Cost performance for all five methods generally varied -5% from budget. Thus, these data do not support a conclusion that project acceleration using the contracting methods studied in this report either substantially increases or decreases costs. Further study may be necessary. There is some indication in the literature that these five methods often increase cost; the data in this survey do not necessarily support the literature. Further, the data indicate that quality is not adversely impacted with implementation of these five methods, contrary to what the literature often indicates and counter to some of the cited disadvantages from survey responses. |