Snap-happy transport authorities have been caught collecting individual information on vehicles - and a privacy watchdog is unimpressed.

The Privacy Commission will be asking the NZ Transport Agency (NZTA) why it has been collecting information on around 14,000 cars a day using controversial automatic number plate recognition (ANPR) cameras.

The cameras, which are different to traffic flow monitors, have been watching four northbound lanes on Auckland's Southern Motorway near the Newmarket Viaduct. Vehicles travelling faster than 85km/h in the 70km/h zone have been targeted.

No speeding tickets were issued because the technology is not up to legislative standard.


The cameras were installed during a $215 million replacement of the Newmarket Viaduct, scheduled for completion in June next year.

The Privacy Commission had not heard about the data collection project, which has cost taxpayers around $300,000, until the Herald on Sunday made inquiries last week.

NZTA's Auckland highway manager Tommy Parks said the cameras monitored the speed of traffic around the construction site, but he would not be drawn on why the details of individual cars needed to be stored. "It's just the data, just traffic survey data. We can now see clearly what the speed profile is.

"We can say to the police the time of day we are getting a particular peak and they might want to do enforcement at that time of day."

Plate details have been collected since May and remain on the database until the end of construction.

Assistant privacy commissioner Katrine Evans said she would be following up with the transport agency next week.

"If they are collecting information about individual vehicles they have to be open about what they are doing. You've got to have a good reason to collect it in the first place and hold on to it," she said.

"We'll have a chat [with NZTA] and see. It's something we weren't aware of. One of the most important things is watching how technology is used; what's being captured and what's being stored."

New Zealand Council for Civil Liberties spokesman Batch Hales challenged NZTA to justify the data collection.

NZTA's Auckland media manager Ewart Barnsley said the data collection had not been disclosed until now. "There was no publicity, mainly because we weren't going to share the information with anybody."