The goals of this project correspond with those of the National Center for Injury Prevention and Control and Healthy People 2010, within the high priority area of studying injuries to child occupants of motor vehicles. Current recommendations from the National Highway Traffic Safety Administration advise that children should switch from rear facing (RFCR) to forward facing child restraints (FFCR) when they reach one year of age or twenty pounds. Preliminary data from Scandinavian countries with an older transition age, however, shows a marked benefit for rear-facing restraints for children up to 4 years old. The proposed project will evaluate this discrepancy between U.S. policy and foreign field experience and, if justified, develop guidelines and recommendations for a revised U.S. policy on the transition from RFCR to FFCR. The proposal involves three mutually supportive research approaches. First, U.S. field data will be used to assess injury risk and define the crash and injury experience of children restrained by RFCR and FFCR. This analysis will provide guidelines for the subsequent proposed tasks. Second, a series of full-scale sled tests will be used to compare and contrast RFCR and FFCR over a range of the most important test conditions. Finally, computational modeling will be used to expand the research matrix to include the range of restraint, crash, and occupant conditions that cannot be assessed experimentally. At each stage of this research plan, an external Advisory Panel will meet to assess the findings and the direction of the research. Once the field, experimental, and computational data are collected, compiled, and evaluated, a formal policy recommendation regarding automobile restraint use for 1 to 3 year old children will be developed and disseminated.