Thousands of commuters will have to make other travel plans and school student's learning will again be disrupted as transport workers and teachers across NSW strike.
The strikes began on Monday with inner-west Sydney bus drivers walking off the job as part of an ongoing dispute over pay equality.
On Tuesday bus drivers in the city's southwest will also strike, before the two groups stage a co-ordinated walkout for two hours during the Friday afternoon peak.
Also on Tuesday train drivers will refuse to drive foreign-made trains that run three-quarters of the services on the network.
Public school teachers and principals will go on strike too, accusing the government of failing to address unsustainable workloads, uncompetitive salaries and staff shortages.
But Education Secretary Georgina Harrisson said the industrial action is a frustrating end to an already difficult year for many parents and carers.
"I want to reassure parents that we are doing all we can to ensure learning continues without disruption - especially given the challenges students, teachers and families have experienced this year," Ms Harrisson said.
But NSW Teachers Federation president Angelo Gavrielatos said workloads were "unmanageable", and a wage cap meant their salaries didn't "reflect the skills or responsibilities they have".
"The NSW government is concerned about children missing out for one day, but we are concerned about children missing out every day because there simply aren't enough teachers," he said.
They want a pay increase up to 7.5 per cent a year to "begin to reverse the decline in teachers' wages compared to other professions".
The union has seized on government and departmental documents showing a "large and growing shortage of teachers" that is forcing them to teach outside their areas of expertise.
Mr Gavrielatos said the government lacked a coherent strategy to fill 3000 vacant positions and recruit the 11,000 teachers the state would need in the next decade.
But Ms Harrisson said the union was being misleading, and the vacancy rate in NSW for teachers is at a low level for an organisation of its size.
It comes as more than 1200 bus drivers in the inner west took strike action on Monday, protesting what they call a two-tier wage system and cuts to services as a result of privatisation.
The NSW Transport Workers Union and Rail, Tram and Bus Union NSW are calling on the government to demand its contractor Transit Systems NSW negotiate with them.
They say it accepted a bid from Transit Systems that left workers at the same depots doing the same jobs, but earning different amounts.
The different pay arrangements have led to more expensive and experienced drivers missing out on penalty shifts and being "rostered out" of the job, they say.
The RTBU has also been negotiating a new enterprise bargaining agreement for train drivers after the old one expired in May.
The union wants an end to privatisation, safety standards maintained and a commitment to retaining current hygiene standards while not relying on contractors to provide it.
Sydney Trains chief executive Matt Longland said the strikes planned for Tuesday are disappointing after more than 40 meetings between Sydney Trains, NSW TrainLink and the union.
Mr Longland said employees had been offered a 2.5 per cent pay increase, inclusive of superannuation.
Transport for NSW said Tuesday's strikes meant services would run to a reduced frequency on most lines, make additional station stops and take longer to reach their destination.
Commuters are advised to plan ahead.
Australian Associated Press