To develop an adequate traffic operations management and congestion mitigation plan for every roadway maintenance and construction project requiring lane closures, transportation agencies need accurate and reliable estimates of traffic impacts associated with pertinent maintenance and construction projects, and the corresponding roadway capacity reductions. The current analytical model used by most agencies for this purpose is based on traditional volume/capacity formulae and deterministic traffic queuing modeling method. New Jersey Department of Transportation recognizes the shortcomings of these methods that often result in inaccurate estimates of the impact of lane closures in terms of vehicle delays and the associated costs. These estimates may be significantly improved by utilizing the probe-vehicle data. The objective of this research project is to develop a methodology for integrating probe-vehicle data into the traffic impact analysis model, and to develop a user-friendly software tool that would implement the calculation methodology.