100,000 passengers use the Tyne and Wear Metro every day.
But on one the busiest shopping day of the year, a breakdown in talks between operator Nexus and the RMT union has brought the service to a halt. All 60 stations and closed and will not reopen until Sunday.
Picketing metro drivers gathered at 4:30am in South Gosforth, Newcastle. They insist the dispute surrounds working conditions, not pay.
Watch Rachel Bullock's Saturday report here:
Visiting the picket line, North of Tyne Mayor Jamie Driscoll was if he supported the strike action?
In a statement, the Tyne and Wear Metro operator Nexus said the strike was ''totally unjustified.''
Saturday was the second day of the strike. Watch Kris Jepson's report from Friday here:
What is happening?
A strike by RMT union members means that there will be no services, across the whole Tyne & Wear Metro network, on Friday 20 December and Saturday 21 December.
Why are they going on strike?
This action is part of an ongoing dispute over pay and working hours. In November, RMT train said no to a 15% pay rise and change to overtime working put forward by operator Nexus.
How has Nexus responded?
Nexus has urged staff to rethink industrial action.
Will there be a lot of disruption?
The action is taking place on the last weekend before Christmas, traditionally a busy time for shopping. Newcastle United are playing Crystal Palace at home on Saturday and fans have been advised to allow plenty of time for their journey.
Has any alternative transport been organised?
Yes but it is in the hands of several different operators.
Stagecoach is putting on extra buses on half-hourly X24 (Sunderland to Newcastle) and X34 (South Shields to Newcastle) routes.
Northern Rail says where possible it will add extra carriages to its trains around the North East and is working with local bus companies to provide additional road transport from Newcastle, Seaham, and Sunderland on Friday and Hartlepool, Heworth, Newcastle, Seaham, and Sunderland on Saturday.
Go North East are increasing capacity and numbers of buses running from South Shields to Newcastle and Sunderland to Newcastle.
Arriva have no additional services that are timetabled officially but they have extra busses that will be deployed as and when required on the routes that get the busiest.
Arrow Cars, the airport's official taxi company, is putting on extra drivers.
Newcastle Airport is not doing anything specific but has warned passengers to make other arrangements.
Watch Kris Jepson's Thursday report here:
Martijn Gilbert, Managing Director at Go North East, said:
Malcolm Bell, Operations Manager at Stagecoach North East, said:
A spokesperson for Northern said: