A review of taxi driver safety following the introduction of cameras in vehicles is underway.
Associate Transport Minister Michael Woodhouse says the review will assess whether the cameras and monitored two-way taxi dispatch systems have improved safety for drivers.
The two measures were introduced in response to a sharp rise in violent and fatal attacks on taxi drivers.
Mr Woodhouse says when those two safety provisions were made compulsory in 2011, the Government committed to reviewing their effect.
The review should be completed by the end of the year.