This report is one in a series which identifies the magnitude, severity, and characteristics of emergency service vehicles involved in traffic crashes occurring in the State of Missouri, and describes Missouri’s emergency service vehicle traffic crash experience between 2002-2004 with emphasis on the most recent year of 2004. The data used in the report were obtained from the Missouri Statewide Traffic Accident Records System (STARS) maintained by the Missouri State Highway Patrol (MSHP). Findings are described in four sections: (1) an overview of Missouri’s emergency services traffic crash problem; (2) a description of the findings from an analysis focusing on police vehicle involvement; (3) a description of fire vehicle involvement; and (4) a description of ambulance involvement. Highlights of report findings include: (1) 1,483 traffic crashes involved 1,526 emergency service vehicles in the State of Missouri; (2) of the 1,526 emergency service vehicles, 350 were on an emergency run at the time of the crash; (3) 7 persons were killed and 432 persons were injured in these traffic crashes; (4) police vehicles (1,150) accounted for the majority of emergency service vehicles involved in crashes; (5) of the 1,526 emergency vehicles involved in 2004 crashes, 203 (13.3 percent) were fire vehicles; and (6) of the 1,526 emergency service vehicles involved in 2004 crashes, 159 (10.4 percent) were ambulances. Tables, figures, and glossary