On June 7, 2012, the National Mediation Board (NMB) published a proposed rule clarifying that it will hold run-off elections under the Railway Labor Act only when three or more options receive valid votes and extended the period for filing comments to August 6, 2012.

The proposed rule revises a May 15, 2012, proposed rulemaking, which suggested the NMB would authorize a run-off in the event of any tie vote. The NMB clarified that, in the event of a tie, it will require a run-off only if votes are cast for at least three options. This clarification should allay employer concerns that a tie between "yes" and "no" votes for a union would permit the union a second election. Under current rules, the NMB dismisses union representation case petitions when there is such a tie and refuses to investigate union election petitions for the same craft or class of employees of the same carrier for one year.