This project builds on current work to apply European and U.S. simulations software on shared use corridors. The objective is to develop a capacity parametric model that uses train timetable and optimization techniques to supplement rail operations simulation analysis toward improved capacity utilization levels of a given corridor. This study focuses on two existing shared use corridors. It will continue the work already initiated on Baltimore-Washington section of the Northeast Corridor and incorporate a segment of Michigan HSR corridor. The study will be based on actual infrastructure, signaling and train characteristics and will use outputs of the European simulation packages (Railsys and/or Opentrack) as well as Rail Traffic Controller (RTC), a common simulation package in the U.S., to evaluate different traffic scenarios and operational variables of the proposed model.