This report documents the effort by the Federal Highway Administration (FHWA) Office of Safety and Operations Research & Development and the FHWA Office of Operations to assess current data sources, to compile existing data, to review gaps, and to propose a data collection strategy that will start to quantify the occurrence of responder struck-by crashes. Often these crashes are not captured in traditional data systems, but they can result in serious or fatal injuries and compromise the safety of the entire roadway system.