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Tractor rollover is one of the most hazardous events fo r the driver. The rollover protective structure (ROPS) was introduced to passively protect the driver. In the specific case of two-post protective structures fitted in front of the driver on narrow-track wheeled agricultural tractors, the ROPS has to avoid non-continuous rolling in the event of a lateral rollover. In order to check non-continuous rolling behavior in narrow-track wheeled agricultural tractors, a mathematical model is included in the preliminary ROPS tests of the standardized testing procedures issued by the Organization for Economic Cooperation and Development (OECD). A recent approach in the design of narrow-track tractors is the fitting of rubber tracks. A safety issue consequent to this new arrangement is that the standardized calculation does not cover narrow rubber-tracked tractors because it was originally developed assuming only the behavior of the tire in a lateral rollover. The aim of this study was to extend the field of application of the standardized calculation for non-continuous rolling behavior, allowing rubber-tracked tractors to be fitted with a front ROPS suitable for operation in narrow orchards and vineyards. The effect of track-ground interaction compared to tire-ground interaction was evaluated. The track shape and nondeformed behavior of the rubber track at a state of unstable equilibrium under full load caused the tractor to rotate around the outer edge of the track; therefore, the tipping axes and wheel characteristics in the original mathematical model were revised. The tracked tractor checked with the revised model required a higher ROPS with respect to the equivalent wheeled tractor to obtain non-rolling behavior. The ROPS needed to be increased by 0.28 m to meet the safety requirement. [ABSTRACT FROM AUTHOR]