Meanwhile Dublin Bus unions are meeting to consider action
The NBRU and SIPTU have agreed to suspend a strike ballot to attend the Workplace Relations Commission (WRC) for talks.
The Labour Court had previously recommended that an independent investigation should be undertaken over claims for a reduction in the working week and a material recognition of past productivity.
All sides have agreed that the issue of driver training will also be on the agenda.
An independent report will form the basis for the discussions.
The NBRU says in a statement: "It is incumbent on all sides to fully contribute towards a resolution to the long drawn out saga of overdue improvements to Loco/Dart Drivers terms and conditions, failure to reach agreement will inevitably lead to both unions coming under pressure to resolve the issue/s through the medium of industrial action."
NBRU General-Secretary Dermot O'Leary says they are looking for better terms and conditions - including a shorter working week and recognition for past productivity.
Meanwhile workers at Dublin Bus could begin industrial action within two weeks, causing traffic chaos for commuters.
The union representing workers, SIPTU is meeting today to decide their next course of action over a long-running pay row.
Drivers want pay rises in line with those recently given to Luas drivers.
They have voted by 95% for strike action.