There is a hoop pine growing at the spot where cattle farmer Anthony Waldron, 68, died after his quad bike slipped down a drop-off, overturned and pinned him to the ground in northern NSW.

The cattle stay clear of the prickly leaves and his family gather there on the anniversary of his death – April 17, 2013 – for a moment of reflection.

Mr Waldron's widow, Jenny, says her husband's death was a "freak accident" but quad bikes have been on her mind following the death of two riders within hours of each other last week.

A six-year-old girl and a 60-year-old man died in separate accidents involving quad bikes on rural properties in the state's north and central west last Sunday.

Less than two months earlier, Connor Irvin, 7, died when he was crushed by the quad bike he was riding on the family farm in south western NSW

There have now been more than 110 quad bike deaths nationally in six years, prompting renewed calls for tougher safety regulations to be introduced.

The NSW Labor Opposition this week called for a bipartisan summit into quad bike safety, and the Royal Australasian College of Surgeons (RACS) has now urged the government to set an age limit for their use.

A new analysis, carried out by technology company Blackhawk, suggests that there could be as many as 90 potentially serious incidents involving a quad bike every day across Australia and New Zealand.

RACS trauma committee chair John Crozier has pressed the government to follow in the steps of a ban introduced in the United States which bans children under 14 years from riding quad bikes.

"This Massachusetts ban of children under the age of 14 years from riding quad bikes nearly halted deaths and has greatly reduced the number of brain injuries in children. Enough is enough. Quad bikes are not toys," Dr Crozier said.

Professor Raphael Grzebieta​, from the transport and road safety research unit at the University of New South Wales, goes a step further. He says all children should be banned from quad bikes, and the legislation should be enacted at a federal level.

A 2015 coronial inquest into nine fatal quad bike accidents across NSW recommended the introduction of mandatory training or licensing for riders, compulsory helmet and seat belt use, and a blanket prohibition on children under the age of 16.

Mrs Waldron supports the banning of children, but she is cautious about other safety measures. Her husband, who had more than 40 years experience riding quad bikes, was spraying weeds on their property when his quad bike slipped down a drop-off, concealed by long grass, and landed on top of him. 

Mrs Waldron said she provides helmets for staff using quad bikes but they are not always practical for certain work and in hot conditions. She is also concerned that mandatory licensing would be expensive for farmers and difficult for those living in rural areas.

"I just don't think they should go over the top with the legislation because we are just over regulated anyway," Mrs Waldron said. "Maybe it should be mandatory that they know the rules and the dangers beforehand. Maybe they've got to read some instructions, watch an online video, and sign a document before they can ride."

The NSW government this week doubled rebates which can be used to buy suitable helmets or safer side-by-side vehicles for riders to $1000. A new quad bike safety video is now also available online.

With Melanie Kembrey