In an effort to motivate contractors to complete construction projects early on high-impact highway pavement construction projects, state transportation agencies (STAs) including TxDOT have often used incentive/disincentive (I/D) contracts. However, determining I/D rates is extremely difficult due largely to the lack of systematic methods for helping STAs determine effective I/D rates. The primary goal of this project is to develop a novel framework for determining the most realistic and economical I/D dollar amounts for high-impact highway improvement projects. To achieve its goal, this project proposes an integration analysis including project schedule and the lower and upper bounds of the I/D contract. The lower bound is the contractor’s additional cost of acceleration, and the upper is the total savings to road users and to the agency. The study data were gathered using Construction Analysis for Pavement Rehabilitation Strategies (CA4PRS) software. These data were then grouped by four different types of pavements, namely Joint Plain Concrete Pavement (JPCP), Continuously Reinforced Concrete Pavement (CRCP), Hot Mix Asphalt (HMA), and Milling and Asphalt Concrete Overlay (MACO). With these data, a series of regression analyses were carried out to develop predictive models for the validation of time-cost tradeoff to determine I/D lower bound. Road user cost and agency cost savings were quantified using CA4PRS to develop lookup tables to determine I/D upper bound. Adjustment of contractors’ additional cost of acceleration with Level of Service (LOS) and total savings adjustment using Net Present Value (NPV) were incorporated in the research study to calculate point based estimates of I/D for lower and upper bound, respectively. Lastly, case studies on real world projects were conducted to evaluate robustness of the model. The research results reveal that the predictive models give appropriate results for the case studies in determining the I/D dollar amount for the lower and upper bound. This study will provide the research community with the first view and systematic estimation method that STAs can use to determine the most economical and realistic I/D dollar amount for a given project–an optimal value that allows the agency to stay within budget while effectively motivating contractors to complete projects ahead of schedule. It will also significantly reduce the agency’s expenses in the time and effort required for determining I/D dollar amounts.

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Road user costs (RUCs) quantify the inconveniences to road users resulting from ongoing construction projects. Although the concept of RUC has traditionally been associated with the life cycle cost analysis, its importance has increased in alternative contracting methods in recent years. Despite its importance, the Tennessee Department of Transportation (TDOT) currently lacks a systematic methodology to compute RUCs. With the increased use of alternative contracting such as A+B, TDOT can benefit significantly if a systematic methodology and a tool are developed to compute RUCs in-house. The main goal of this study is to develop a framework and accompanying tool to compute RUCs, which balances the ease of computing and accuracy of results. To achieve this goal, the study reviewed existing literature on the topic, conducted a nationwide survey, and identified the current best practices of calculating and utilizing RUCs. The study found that more than half of the state Departments of Transportation (DOTs) that responded to the questionnaire have developed their state-specific methodologies to compute RUCs. The delay costs and the vehicle operating costs are the two most common components computed by a majority of state DOTs. Based on the findings of the study, a framework to compute RUCs is developed to enable TDOT to quickly compute RUCs more efficiently. Subsequently, a spreadsheet based TDOT RUC Calculation Tool (TRCT) is developed to implement the framework. The tool can compute four components of the RUC: a) delay cost, b) vehicle operating cost, c) crash cost, and d) emission cost. Relevant standard datasets such as median household income and emission rates were collected and/or produced for the tool. The tool automatically accounts for the spatiotemporal variation in the RUCs using Consumer Price Index (CPI) and county-specific data. The computed RUCs can be used for A+B contracting, benefit-cost analysis, liquidated damage computation, and early-completion-incentive computation.

Construction zones can greatly affect the traffic flow on roadways, especially when lane closures are required. Traditionally, the Utah Department of Transportation (UDOT) has used traffic management specifications that only allow lane closures and road work to be done during predetermined hours or specifications that require a certain number of lanes to be open at all times. Recently, mobility-based work-zone traffic flow maintenance has been considered. This method requires continuous monitoring of mobility-based performance data and a mechanism to send alerts to the contractors when the mobility data does not meet the standards set by the specifications. UDOT recently tested mobility-based performance specifications at an urban arterial work zone and studied issues related to implementation of mobility-based performance specifications. Parallel to this experiment, UDOT funded a study to develop guidelines for implementing mobility-based performance specifications to manage traffic flow in work zones. Dynamically collecting mobility-based data such as travel time and speed is now feasible using technologies such as Bluetooth and microwave sensors. The core benefit of using mobility-based performance specifications is that they can give the contractor more flexibility in construction work scheduling while maintaining an acceptable level of traffic flow. If the level of traffic flow is not maintained, then the contractor is assessed a financial penalty. The penalty is determined by the amount of time where the flow is not maintained at a predetermined condition. To discuss issues and develop guidelines, a task force consisting of UDOT representatives, several representatives from the construction industry, and researchers from Brigham Young University was formed. Through three task force meetings, a set of 12 guidelines were developed, including guidelines about when mobility-based performance specifications should be used and which mobility data should be used. Some of the issues were difficult for the task force members to agree on, and a decision-making theory called the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was used to find best approaches to deal with some of the difficult issues associated with the implementation of mobility-based performance specifications in highway construction contracts. These guidelines should be reviewed as appropriate in the future as UDOT accumulates experience in using these types of specifications.