More than half of the 150 quad bike farm incidents recently investigated by researchers involved accidents where riders were moving livestock.
Dr Dave Moore, of the Scion Centre for Human Factors and Ergonomics, said 76 incidents involved livestock, but about 50 of those cases were from when riders were moving stock, got distracted and had an accident.
In some cases, this involved being led by animals on to unsuitable terrain where drivers got into trouble.
Dr Moore said this highlighted the difference between the recreational-design of quad bikes, and how New Zealand farmers have turned them into mini-tractors.
Farmers told him when shifting stock, they often replaced their dogs with a quad bike, riding on the machine to chase animals.
They soon realised they could not anticipate the actions of animals and monitor the safety and suitability of the terrain where they were riding their quad bike.