Auckland Transport refuses to say if it will keep giving passengers with only old purple Snapper Hop cards free trips on buses equipped with newer technology.

That is despite a revelation by a bus drivers' union leader that NZ Bus has told staff not to turn away passengers with the wrong card for now.

The council transport organisation allowed passengers without its new dark blue AT Hop cards free rides yesterday, after almost half of the 294-strong Metrolink bus fleet switched to its $100 million electronic ticketing system at the weekend.

Spokeswoman Sharon Hunter said the grace period was for a minority of passengers who might have missed extensive advertising of a need to carry both cards - or cash - while all NZ Bus subsidiary fleets are changed to the AT Hop system between now and the end of the year.


Asked how long the freebies would continue, she said: "I can't say, but it is very brief - that's about to disappear, so get with the programme."

But Auckland Tramways Union president Gary Froggatt said NZ Bus had told drivers not to kick people without the correct card off buses until the rest of its Metrolink fleet switches to AT Hop on November 24.

He said changing half of the fleet at a time was "absolute nonsense".

"It's too confusing - it should have been done together."

The weekend swap involved buses based at the company's central city and Panmure depots, leaving those operating from Onehunga and Mt Roskill to follow in a fortnight.

Its North Shore buses changed over last month, and its Go West and Waka Pacific fleets are due to change to AT Hop next month.

Ms Hunter said the Metrolink fleet was too large for all buses to swap in one weekend, without disrupting scheduled services.

She said bus officials reported the latest semi-rollout had gone reasonably well "from both a technical and customer perspective".


But passenger Fiona McKinney, who took AT advice and made sure she got an AT Hop card in time, said she was frustrated at being made late for work yesterday "thanks to the huge numbers of people hopping onto my bus who obviously weren't smart enough have noticed the extensive advertising campaign.

"If they had been paying attention like I have, they would know they can get transferred to the new card."