Corridor System Management Plans (CSMP) are performed by Caltrans, in conjunction with all appropriate jurisdictional agencies, to assess current and future deficiencies in a transportation corridor and determine necessary future traffic management, transit, and infrastructure improvements for meeting mobility goals. Caltrans, the Contra Costa Transportation Authority (CCTA), and System Metrics Group (SMG) are developing a CSMP for the I-680 corridor between I-580 and the Benicia Bridge. The aim is to determine the best mix of strategies to improve mobility, travel time reliability, and stewardship of existing resources, based on analysis of extensive modeling and other evaluation tools. PATH is supporting this effort by providing simulation capabilities for scenario testing and planning exercises, with the goal of demonstrating that our recently developed Tools for Operational Planning (TOPL) can make CSMP development faster, easier, less expensive, and more effective than is possible with existing technologies.