If the NMB determines that the bargaining dispute threatens to interrupt interstate commerce, it will notify the president of the United States. The president can then choose to appoint what is known as a Presidential Emergency Board (PEB) to investigate the dispute and recommend solutions. If a PEB is appointed, the RLA imposes additional cooling-off periods.

When faced with these circumstances in national freight rail bargaining, the president typically appoints a PEB. Under the RLA, the president selects the size and members of the PEB. Once appointed, PEB members (typically experienced professional arbitrators) have 30 days to issue a report with their findings and non-binding recommendations for a resolution.

Throughout this process, parties are prohibited from engaging in “self-help” tactics.