New rules for companies taking trampers to the Tongariro Crossing should help prevent a repeat of last month's incident where 16 ill-prepared trampers, some close to death, were rescued from freezing conditions.

The Department of Conservation says it will require Tongariro transport and guiding concession holders to be members of the Tongariro Alpine Crossing Transport and Guide concessionaires group and abide by its safety protocols.

The group has rules that say operators will not transport trampers to the 19-kilometre crossing if the weather is unsuitable or they do not have appropriate clothing and equipment.

Group chairman Stewart Barclay says the group has a 12-month goal to have all Tongariro Crossing transport and guiding concessionaires signed up as members.

The group wanted to ensure the safety protocols set standards above legal requirements, "to a level where we are confident we are meeting our moral and professional responsibilities," Mr Barclay said.

Local conservator Damian Coutts told NZ Newswire the move was a response to last month's near disaster and other recent incidents.

Police Ruapehu area commander, Inspector Steve Mastrovich, says police endorse the move.

"We believe this will empower the operators to apply consistent practices on the crossing."

In April, 16 inexperienced trampers were rescued from Mt Tongariro, some shaking, hysterical and close to dying from hypothermia, according to their rescuers.

The group did not have alpine clothing, despite low visibility, strong winds and very cold conditions.

Police criticised transport operator Mountain Shuttle - said to have told the trampers the weather would improve - for encouraging the group to proceed.