Transport Minister Phil Twyford said the recent bus crashes are a real cause for concern and he has asked the Ministry of Transport and the NZ Transport Agency to look at the incidents.
The investigation comes after Taranaki bus driver Allan Campbell (69) was killed after his vehicle left the road and crashed into a ditch on State Highway 3 on Wednesday.
There were 13 passengers aged 12-17 on the bus at the time of the crash. Ten suffered minor injuries.
The incident was the second fatal bus crash in a fortnight and the third serious crash involving a bus.
Last week, 19 people were injured after the bus they were travelling in crashed into a ditch alongside State Highway 1 in the Manawatu.
Another bus crash on Mt Ruapehu killed 11-year-old girl Hannah Francis when the vehicle she was travelling in rolled near Turoa skifield on July 28.
All three buses involved in the crashes were Mitsubishi Fuso models, though the bus in Wednesday's crash was said to be a ''totally different'' type of vehicle and much larger.
''Three crashes in quick succession, lives lost, a lot of injuries. We need to look at this and see what lessons we can learn,'' Mr Twyford said.
The investigation would allow him to see the facts and identify if there were any common elements within the three crashes.
''I have asked the Ministry of Transport and the NZTA to look at these three incidents and first tell me whether ... the certificate of fitness testing has been implemented with sufficient rigour.
''Secondly, I want them to look at all three cases and see whether there are any common elements that we can learn from.''
Other issues to be looked at were the age of the vehicles and whether seatbelts needed to be compulsory in buses, he said.
When asked whether the issue was with Fuso buses, Mr Twyford said, ''I can understand why people would jump to conclusions based on the fact that the three incidents have involved buses of the same type, but ... there may be other factors at play here.''
The ministry would look at the incidents from a policy perspective and NZTA would take a more operational approach.
''They will come back with a report and we will see if there are any further actions required.
There was not a time limit on the report but he expected it would be submitted within the next few weeks.
