In his formal written findings into the deaths of two Chinese tourists near Milford Sound in 2011, released yesterday, Mr Crerar recommends police and the NZTA take a tougher stance on enforcing regulation of overseas drivers.
NZTA media manager Andy Knackstedt said yesterday the agency would review the recommendations and discuss them with the Ministry of Transport before responding.
Chinese nationals Xing Liu Yu (57) and Yichin Luo (56) were passengers in a rental car being driven by a Chinese woman who had twice failed her practical driving test in New Zealand.
Mr Crerar found Wenling (Vivien) Dong, who was driving the Subaru Forester, had failed to turn on the car's ignition before she coasted away after stopping at a viewing point on State Highway 94, near the western portal of the Homer Tunnel, meaning the car's steering remained locked.
When Ms Dong failed to negotiate a bend the car left the road, hitting a rock about 8m below the road edge, the vehicle's airbags did not deploy.
Neither Ms Yu or Mr Luo were wearing seat belts; expert analysis indicated had they been restrained ''at least one of them would have survived''.
Mr Crerar said under the Land Transport (Driver Licensing) Rule 1999 visitors to New Zealand could drive under a valid and current licence or permit, issued by an overseas authority.
Ms Dong held a Chinese licence and had applied for a New Zealand licence, passing the theory test. She was issued with a learner's licence, which carried a ''supervisor condition''.
In September and October 2011, Ms Dong attempted and failed the practical driving test and, because she held a New Zealand licence, her Chinese licence was no longer valid.
''Notwithstanding this, Vivian Dong, knowing that her New Zealand learner's licence would not be acceptable to Apex Rentals, presented her Chinese driver's licence for the purpose of renting the Subaru,'' Mr Crerar said.
The rental agreement, dated November 27, 2011 and signed by Ms Dong, designated her as the authorised driver and said the vehicle could not be driven by anybody who did not hold a current full driver's licence.
None of the passengers was an appropriate supervisor, as required, he said.
''There appears to be a lacuna [gap], either in the law or the enforcement of it, which has allowed this scenario to develop and be perpetuated.
''I have been made aware of a practice in Australia in which the driver's licence issued in an overseas jurisdiction is marked as soon as a domestic driver's licence is applied for or obtained to show that it is no longer valid.
''I will arrange for a copy of this finding to be forwarded to the Commissioner of Police and to the NZTA so that the difficulty, and solutions to it, can be further considered.''
He also recommended both parties examine the issues relating to overseas drivers obtaining and presenting New Zealand driver's licences ''with a view to ensuring that in future a stricter enforcement of driver's licence requirements for visitors to New Zealand are made''. He also called for the NZTA to give greater publicity about the obligations of passengers in motor vehicles to wear seatbelts at all times when the vehicle is moving. Following an inquest in Invercargill on April 15, Mr Crerar found Ms Yu and Mr Luo died on December 7, 2011 from injuries sustained in the crash.
Ms Dong initially faced two charges of careless driving causing death and one of careless driving causing injury, but the charges were later withdrawn.
In her evidence, Ms Dong said she thought the vehicle had stalled.
However, Mr Crerar was required to ''balance the possibilities and the probabilities''.
''It is accepted there is a possibility of an engine stall having occurred due to fuel starvation ... or other engine faults.
''The probability, which most of the unchallenged and incontrovertible evidence supports, is ... when leaving the car park at the viewpoint, the engine of the Subaru was not turned on.''
Mr Crerar said when the vehicle was recovered, the key was in the ''off'' position.
While there was a remote possibility the key had been turned off either by Ms Dong after the crash or during the vehicle recovery, ''these are remote possibilities only''.
Subaru agents said airbags should deploy on impact and for up to 10 minutes after the ignition was turned off.
Because none of the six airbags had deployed, it gave more weight to the vehicle having not been turned on again after stopping.
Following the crash, a meeting between NZTA, road engineers Opus and road maintenance contractors Downers resulted in an agreement a guard-rail be installed on the corner.
