Convened by Transportation Research Board, the Workshop on Traffic Simulation and CAV Modeling will be held as a virtual event November 16-18, 2020. Transportation system simulation is widely used to support the business processes of transportation agencies including those related to planning, design, operation, management, and safety of increasingly complex multi-modal transportation systems. The advent of connected, automated, shared, and electric (CASE) vehicles provide challenges to be addressed with simulation.  This virtual workshop will bring together researchers, vendors, and users of transportation system simulation to identify persistent challenges, discuss solution approaches, present recent research findings, and identify future research needs related to traffic simulation modeling. The discussions will focus on the history, status, and future of traffic simulation, plus modeling of CAVs. The workshop includes invited panels, sessions based on a call for papers/posters, and breakout sessions.