The transportation infrastructure systems in the United States were built between the 50's and 80's, with 20 years design life. As most of them already exceeded their original life expectancy, State Transportation Agencies (STAs) are now under increased pressure to rebuild deteriorated transportation networks. Over the recent years, state transportation agencies (STAs) have taken into consideration various project delivery approaches apart from conventional project delivery approach to expedite project delivery. Since the introduction of these new alternative delivery approaches, not many substantial studies were conducted that evaluated the performance of these new alternatives. The absence of systematic studies about the effectiveness of these strategies and lack of appropriate analytical tools to evaluate them inhibits the STAs from budgeting precisely and accurately these strategies when they are deliberated for being put into practice. This study tries to address these limitations by evaluating the effectiveness of these strategies. The major objectives of this research were: 1) to evaluate the impact of contracting strategies on dealing with change orders 2) to evaluate the performance of different contracting strategies under varied work type for the state of Florida . For this research the study was conducted to quantify the changes to project duration and cost caused by change orders in the project under different contracting strategies and type of work. This was done through evaluating 2844 completed transportation infrastructure projects, completed between 2002 and 2011 in the state of Florida. These projects comprised of both the conventional projects and innovative alternative projects. The data was then statistically analyzed for evaluating the performance of these contracting strategies. The research concluded that alternative contracting strategies perform much better than conventional contracting in controlling project schedule but are found not to be as effective in controlling the project cost growth. The study also established that project size and work type affect the effectiveness of the contracting strategies. The study indicates that A+B is the worst performing contracting strategy among all the strategies evaluated. The results of this study will help the STAs to make better informed decision regarding selection of contracting strategy for project delivery.

The negative impacts associated with highway pavement rehabilitation projects drove state highway agencies (SHAs) towards increased adoption of alternative contracting methods (ACMs) to accelerate the construction of such projects; hence, reducing these impacts on the travelling public. However, the application of such methods showed mixed results due to the lack of specific guidelines addressing the adoption of such methods and the selection of the best ACM for each project. This lack of guidelines stems from the lack of research studies examining the impact of each of these methods on the time/cost trade-off relationship in highway rehabilitation projects. Existing literature includes several studies aimed at developing generic and subjective guidelines based on past experiences that do not take into consideration the unique nature of each of these methods. Hence, this research study aimed at analyzing the SHAs’ decision making process regarding two of the most-widely used ACMs: Incentive/Disincentive (I/D) and Cost + Time (A+B) contracting methods, in order to support decision makers in choosing the most-suitable method for their projects. To this end, two models were developed in this dissertation to examine the time/cost trade-off for each method using simulation and regression analysis. Each model was validated against real-life projects and used to assign appropriate ID and “B” values based on the SHA’s desired duration reduction and available budget. Furthermore, a risk analysis module was developed to determine the most-likely duration reduction that the contractor can achieve for each project under each method. The developed models should help improve the decision making process regarding the selection and implementation of these methods in highway rehabilitation projects. For example, the models can help SHAs identify the minimum ID level that can be offered for each project and the expected duration that the contractors can bid on under the A+B contracting method. Finally, the models were contrasted and applied to real-life projects with different characteristics to verify existing guidelines and establish the candidate ACM for each project category. The findings of this study will benefit the society, SHAs, and the economy in general by optimizing the use of available time and money resources.