Bus companies are being given a 12-month grace period to ensure they give drivers rest breaks, but disruptions are still expected.
It's all part of a Memorandum of Understanding signed by local councils, the Council of Trade Unions and the government, after warnings of mass cancellations of services if companies were forced to comply.
The rest-break legislation, due to come into effect next Monday, will require that drivers receive a 10-minute break every two hours, and a 30-minute break every four hours.
Minister of Transport Phil Twyford this month accused bus companies of "catastrophising" the situation and that it should be within their ability to find a solution.
He said the new rule he and Workplace Relations and Safety Minister Iain Lees-Galloway announced today would allow companies "maximum flexibility" on how those breaks would be applied.
"The bus companies needed some assurance that the unions would support them, taking a very flexible approach to timing the breaks in order to avoid extra cost or disruption of services," he said.
However, he admitted the new law would completely prevent disruptions when the law comes into effect.
"We can't give an iron-clad guarantee, this is a very complex and challenging thing that we're dealing with, I think that most of the bus services will be able to accommodate a break for the drivers without any trouble, a proportion of them will require some rejigging, and there may be a small number where services may be disrupted."
New Zealand Council of Trade Unions president Richard Wagstaff said the flexible approach was not ideal but it was an improvement on current conditions.
"Bus drivers haven't had rest breaks before and now we're going to get rest breaks for bus drivers so that's a real advance."
"We're not expecting any bus driver or any bus company to be exempted from this process, it's just a matter of creating some space to work out the logistics."
The Memorandum of Understanding also commits councils, unions and bus companies to addressing workforce issues, reviewing compliance with worktime rules, and achieving a living wage.
It states that unions will avoid industrial action relating to these matters for the next year.
The Bus and Coach Association's chief executive Barry Kidd said in a statement that bus users should consider alternative modes of transport if their service was affected.
More resourcing of drivers and buses were required to meet the legislation, he said.
The councils, NZTA and bus companies were yet to decide how the bill for those extra buses and drivers would be divided up.