With the increasing number of road rehabilitation projects across the United States, the need to reduce user costs due to congestion is more important than ever. The Utah Department of Transportation (UDOT) has proposed replacing two I-80 bridges over Echo Dam Road and Weber River in Summit County. The proposed project includes removal of the existing structures and approaches, followed by construction of the new bridges. The proposed structures will be designed and built to allow for future bridge deck replacement while maintaining two-way traffic. The method of bridge replacement will be Accelerated Bridge Construction (ABC). This study evaluates the impact of proposed replacement on the travelers in Summit County. The purpose of this research is to provide UDOT an estimation of possible delay costs due to congested traffic resulting from the proposed work zone scenarios. The VISSIM micro-simulation tool is used to build and calibrate the models. Hourly traffic volumes, provided by UDOT, are added as vehicle inputs into the model. Two work zone scenarios were developed by UDOT: Echo and Weber River. In each scenario, one direction of traffic is closed at a time, while the opposite direction remains open for traffic. For the closed-direction, ramps are used as detours. Both these scenarios are simulated and user delay costs are measured separately. Results for both the Echo and the Weber River scenarios show that the average daily user delay cost is lowest on Mondays and Tuesdays. This suggests that UDOT can complete the proposed ABC work on these days, to ensure minimum traffic disruption to travelers. The future work consists of estimating user delay costs caused by the replacement of the bridge on 2300 East on I-80. Similar analysis is required to determine the day of the week that would have minimum daily user cost.