Long Island Rail Road's largest union has unanimously voted to strike, with a walkout possible as soon as March.
Members of two locals that make up the Sheet Metal, Air and Transportation Union cast their votes Wednesday.
A labor stoppage could come on March 21 unless a contract agreement is reached or the MTA asks the White House to intervene with a second Presidential Emergency Board.
Commuters like Jamie Ard, who takes the LIRR to Rockville Centre from Manhattan, say a walkout would be disastrous.
"I'm getting a graduate degree on Long Island. It would mena I couldn't could go to school," she said.
Laura Rand, who takes the train to Brooklyn on the Port Washington line, said, "It would kill my commute to Brooklyn every day."
LIRR unions have been without a contract since 2010. Anthony Simon, the general chairman for the 4,400 ticket takers, track workers and metal workers in the Sheet Metal, Air and Transportation Union, says his members don't want to inconvenience the public.
"Those are our neighbors. Our kids go to school together," he said. "We don't want to go on strike, that's what we're trying to tell the MTA."
The MTA rejected the first board's recommendations. Spokesman Adam Lisberg said sticking points include changes in work rules, which could dramatically reduce overtime.
The MTA wants those concessions so it can accept what federal mediators recommended: a 3-percent salary bump for workers, who would then contribue to their health care for the first time.
"Everybody else has sacrificed," said Lisberg. "We think this is a reasonable accommodation."
"The MTA believes workers deserve a raise. The best way to do it is to make some common-sense work rule changes," he said.
The request for the second board would put off the strike until July at the earliest.
Smaller LIRR unions have approved similar votes to walk off the job.
The railroad carries 300,000 daily commuters.