The location, type, and local mechanism of tibial shaft fracture were determined for 66 drivers injured in frontal automobile crashes. The results from the analyses showed that the distal third is the most common fracture location (p<0.05) and that bending is responsible for the majority of these fractures regardless of the fracture site. These findings indicate that the current injury criterion for predicting the occurrence of tibial shaft fracture in crash tests with anthropometric test devices is appropriate in terms of accounting for the primary mechanism of fracture but that increased protective effectiveness could be achieved by redefining the criterion for the distal third shaft section instead of the currently specified mid-shaft section of the tibia.