They were in a group of 16 who travelled to the central North Island in a two-car convoy.
Police said after the crash it appeared the driver over-corrected after drifting onto gravel on the left side of the road.
Yesterday, Bay of Plenty road policing manager Inspector Kevin Taylor told the Herald the van had a current warrant of fitness and registration but was undergoing a full mechanical inspection.
Mr Taylor today said the decision to charge the driver was not taken lightly and would have a major impact on him.
"However we are faced with a situation where three people have died and others are seriously injured and we must apply the law in an objective and dispassionate way.
"The process from here is that the case will be put before the court. Once the court process is concluded it will then be for the Coroner to make the final determination about cause of death.
"We have ruled out any use of drugs or alcohol by any of the young people involved, including the driver.
Victim's family: 'We feel their pain'
The parents of a 21-year-old woman critically injured the a horror van crash have offered sympathy to the family of a student charged with causing their daughter's injuries.
Boston University Meg Theriault was put in a medically induced coma after receiving life threatening head injuries in the crash.
A statement issued on behalf of Todd and Deb Theriault said they had met Mr Houseman's parents and understood their pain.
"We feel their pain and he now has a journey of recovery much like our daughter does.
"We understand there needs to be a court process and we support it.
"But that could have been any one of our kids at the wheel. This was an accident - all our kids were pursuing their dream. Nobody was intentionally doing anything that would harm anyone."
Waikato DHB said Meg remained in a critical condition but was breathing on her own for the first time since she was admitted to intensive care.
Mr and Mrs Theriault said their daughter was a fighter and her progress was encouraging.
"We could not have fathomed how much support we would get, from everyone we encounter. You Kiwis are special people."
A remembrance service for the dead will be held at Auckland University tomorrow.