Almost 100,000 people have had to alter their travel plans today as a result of another Luas strike.
An all-day work-stoppage - the 11th strike day at the company - is underway, with several more days of action planned for this month and next.
Yesterday, drivers rescheduled some of their planned strikes in June, so they would not affect secondary school students sitting State exams.
Three more days of industrial action are planned for May 20, 26 and 27.
Mark Gleeson of Rail Users Ireland said commuters had had enough.
"Commuters are fed up," he said. "There's no resolution in sight. Commuters are asking why this isn't getting resolved, why unions and management at Transdev can't solve the problem.
"Using commuters as pawns is not acceptable."
The union representing drivers said they were open to compromise on their demands, and urged Transdev to return to talks.
SIPTU's Owen Reidy said: "The sides have to share some responsibility. We are available to talk and we want to do a deal. We are prepared to compromise, but we can’t do that if the employer won't let us into the room."
Transdev management said yesterday they would reengage with talks if drivers could indicate there was a solid basis to do so.
The June strike sdays will be for four hours each day on Thursday 2 and Friday 3, then during the 7, 8, 9 and 10 of June.
To accommodate Junior and Leaving Cert students, the times on relevant days have been adjusted so that on Wednesday June 8, Thursday June 9 and Friday June 10, the four-hour stoppages will be between 6pm and 10pm.