"Although we're working hard to update cancellations in our system, there may be some occasions when these are last-minute and can't be communicated in time.
"To help minimise disruptions, AT is supporting operators to get staff back to work safely, through the use of Rapid Antigen Tests."
AT said the number of passengers had dropped to 31 per cent of pre-Covid levels.
The situation has frustrated commuters who rely on public transport.
Grey Power North Shore president Bill Rayner said a lot of elderly people use public transport to get around, and so last-minute cancellations left them vulnerable.
"A lot of older people have mobility issues and so if they're suddenly faced with having to walk a long distance, that is a serious issue.
Auckland Transport has confirmed it is cancelling about 2,000 services a day due to staff shortages. Photo / Michael Craig
"Auckland Transport needs to be very careful not to leave people in a difficult situation, and adequate notice must be given."
Public Transport Users Association chairman Niall Robertson said although it was understandable there were staff shortages because of the outbreak, AT was still responsible for keeping commuters informed of service changes.
"AT really needs to get on top of its communication because some people are still being left in the dark.
"I was recently at a train station and there were absolutely no signs or notices to indicate changes to the schedule."
He said some commuters might give up on public transport.
"People go to a great deal of trouble to get to a bus stop or train station, so when they find out their service is cancelled or going to be late it can be very annoying."
AT has also warned some schools of potential bus cancellations.
"We are trying to run most school bus services to a regular timetable. However, we are expecting to see last-minute cancellations due to the spread of Omicron."
The organisation said people wishing to take public transport should do so with confidence.
"There is plenty of room on board for people to travel safely, and public transport is a low-risk setting when you're wearing a mask."
For the latest updates on service changes, people are being urged to check Auckland Transport's Live Departures section on the AT website or on the AT Mobile app.
