Investigation of Quad Bike Rollovers in the Workplace Farm Environment

Around 70% of workplace quad bike crashes have involved the quad bike rolling over. Despite this, limited information is known about the circumstances of quad bike crashes, specifically how rollover crashes occur in the workplace. It has been hypothesised that quad bikes ridden by a rider who is preoccupied by the work task are particularly susceptible to rollover caused by small asymmetric bumps (i.e. placed in line with the wheels on one side of the quad bike) traversed at low speed on moderate slopes in typical workplace farming environments, which can lead to the crushing and asphyxiation of the rider. A cross sectional survey identified that the quad bike rolling over the rider compared to not rolling over the rider is the risk factor associated the highest odds of serious injury in rollover and lateral rollover crashes. Additionally, the survey identified that surface irregularities including bumps as well as turning compared to impacting a fixed object were associated with the highest likelihood of a quad bike crash resulting in a lateral rollover. Finite Element (FE) simulations identified that quad bikes are vulnerable to rolling over as a result of traversing relatively small asymmetric bumps on moderate slopes at speeds typical of the farming environment. These results suggest that users and owners of quad bikes need to consider seriously whether this type of vehicle is safe for performing their required workplace tasks. If it is likely that the vehicle will be used on rough/uneven moderately sloping terrain with the potential for the rider’s focus to be on the work task, it appears that a quad bike is not a suitable vehicle for the task and an alternative more stable vehicle should be used. The final study of the thesis, which was performed as an extension of the FE model’s capabilities, identified that clipping a roadside feature with the wheels on one side of a quad bike with a seated rider, can cause a rollover. Hence, quad bikes are also vulnerable to bumps found on public roads and should not be permitted to drive on them