Doctors have welcomed tighter quad bike regulations making roll bars mandatory but say children under 16 should also be banned from riding the farm vehicles.

Paediatric surgeon Dr Warwick Teague, from Melbourne’s Royal Children’s Hospita,l says children and the four-wheeled devices are a “toxic mix”.

He has been campaigning on the issue after seeing a number of quad bike injuries, among them crushed pelvises and fractured skulls.

“These are harrowing injuries with long-term disability and wide-ranging impacts on the family,” he told Fairfax Media.