Auckland Transport (AT) is reviewing its safety procedures in response to an increase in the number of attacks on bus drivers.

Over the last two years, there have been 36 assaults against AT drivers - a figure the transport service admits is too high.

AT bus service manager Darek Koper said "we need to do more and we are working with bus operators to do a lot more to reduce the risk, to minimise the risks the drivers are facing".

Most recently, an Auckland bus driver was attacked by three thugs on her route in Māngere three weeks ago.

The driver, who was afraid to be identified, told 1 NEWS she was physically assaulted after refusing to hand over the vehicle's cash box, which contained around $60.

"I kicked and punched back but with three of them against me, they overpowered me and threw me off the bus," she said.

"I had bruises on my legs, on my stomach."

According to FIRST Union, which represents the majority of bus drivers, nearly half of their members nationwide have been attacked either verbally or physically.

"We need to have AT and council and the companies seriously sit down together and talk about what they're gonna do," said Emir Hodzic, FIRST Union's transport organiser.

AT says it's taking steps to improve safety for bus drivers, including rolling out CCTV on its entire fleet, giving drivers training to deal with difficult passengers, and putting security guards on more risky routes.

It's also considering operating cashless vehicles.

However, the bus driver says change can't come soon enough.

"A lot of our other drivers have been attacked as well, and some of them have even resigned because of it. I'm thinking of resigning because I fear for my safety," she said.

Police are continuing to investigate the recent attack and say they have strong lines of inquiry.