Twenty-two bus routes in South Auckland have been cancelled for much of the day due to strike action.
The Ritchies-Murphy routes affected are across Manukau, Manurewa and Weymouth.
Today is the second day members of the First Union have walked off the job, calling for better pay and working conditions.
First Union organiser Emir Hodzic said Ritchies-Murphy was ignoring the needs of drivers.
Some shifts could result in drivers being away from home for 11 hours a day, he said.