Surely the way to negotiate and, at the same time, not antagonise and inconvenience the paying public is to devise a means whereby the service is kept going but no money is collected for the fares. Issue "you owe us" notes, perhaps, to be squared at a later date. That is not stealing, just delaying payment. When I was in France I experienced strikers on the motorway "peages" letting the traffic roll, free, gratis and for nothing under the eye of "les flics".