TRB's E-Circular 226: Transportation System Resilience: Preparation, Recovery, and Adaptation explores research issues related to implementing transportation systems resilience, and explores themes of a whole system approach to resilience, weather and advances in forecasting, an integrated approach to cyber-physical security for transportation, a European perspective on research for resilient road infrastructure, training and recruiting qualified employees who can assist during adverse events, and improving the resilience of transit systems threatened by natural disasters.