Operator interface for tractor rollover mitigation system

Tractor rollover incidents are responsible for the death of approximately 200 U.S. farmers every year. Tractor operators are often incapable of predicting overturn, and once a tractor reaches its critical overturn angle, operator response times are too long to allow them to take corrective action. Research conducted at the Pennsylvania State University has resulted in a sensor and information display system for farm tractor overturn mitigation. The system includes a full-color LCD in-vehicle stability display to alert tractor operators of potential overturn conditions identified by the stability sensors. This paper contains a brief discussion of the rollover sensor system, but focuses primarily on the critical human factors considerations underlying the development of the operator interface. Some of the topics discussed include selecting the optimal warning signal modality (i.e., visual, auditory, haptic, or multimodal), the optimal frequency and intensity of the warning signal, optimizing the interface for the two groups most prone to turnover crashes (i.e., younger and older operators), and the impact on experienced operators of using a conservative warning threshold level with the potential for false alarms.