Some 634 accidents occuring in races sanctioned by the Sports Car Club of America (SCCA) are reviewed. Shoulder harnesses were used in 275 of the accidents. Inverted “Y” or double, separately anchored, shoulder harnesses were used almost exclusively. A significant decrease in the frequency and severity of injuries occurred after harnesses were introduced. Injury from the restraint system was very infrequent; submarining occurred only once. Deep bucket seats, providing lateral support for the chest and forward support for the buttocks, appear to potentiate the effectiveness of restraint systems. The “Y” harness functions well in production seats without lateral support because lateral displacement of the shoulders and upper torso can occur without risk of neck injury.