Bus passengers are being warned to expect delays as three days of industrial action begins.
Employees from Arriva depots, including the one in St Helens, will walk out on Thursday October 19 in a dispute over pay.
Union GMB has also called strike action on Monday October 23 and October 30.
The move comes after a pay offer by Arriva was rejected, with the union saying it was a rise of just 31p per hour and amounted to a pay cut as it was below inflation.
The St Helens depot is one of 11 across Merseyside involved in the dispute.
Eddie Parker, GMB Regional Secretary, said: “GMB’s hard-working Arriva members just want a fair deal, like everybody else.
“The final pay off made by the company represents an increase between 1.6 per cent and 2.6 per cent.
“Yesterday inflation hit three per cent, so this is in effect a real-terms pay cut for members.
“No one wants to go on strike and our members are taking industrial action as a last resort.
“With 11 sites affected across Merseyside commuters should be aware of potential traffic chaos.”
Arriva said none of its scheduled services in Merseyside or Greater Manchester would run on the strike days and criticised the union for the walk-out.
Arriva North West managing director Phil Stone said: “It is disappointing that following a further meeting with Unite and GMB yesterday and two improved offers being made they are proceeding with disruptive strike action. We believe that we have tabled a fair pay deal for our drivers in the region.
“Arriva North West wholeheartedly apologises to our customers for the disruption this strike action will cause to their journeys.
“We remain committed to working together with UNITE and GMB to reach a mutually acceptable outcome, however any pay increase has to be sustainable for the business going forward. We are urging our trade union colleagues to reconsider their position and get back round the negotiating table and call off the strike action that will unnecessarily disrupt many thousands of passengers.”
St Helens customers with pre-paid tickets will be able to use them on the Merseyrail network on all three strike days and all Arriva tickets will be accepted on Stagecoach Quality Network Routes.
For more information ring 0344 800 44 11, search for Arriva North West on Facebook or follow the company on Twitter @arrivanorthwest