The tax increase would generate an estimated $40 billion over 30 years that would be used to fund numerous transportation projects in L.A. County.
Mayor Antonio Villaraigosa, who is now the head of the MTA Board, is spearheading the push for the ballot measure. One of his main projects would be to build the Subway to the Sea for the Westside.
Opponents say his push for the Subway to the Sea is one of their main concerns. They say they're worried the money isn't going to be spread evenly around the county, like funding the next extension of the Gold Line out to Montclair.
The Mayor says without the funding the MTA is out of money for future projects.
"It's an opportunity for us to move Los Angeles and the L.A. County region into the 21st century, investing in public transit," said Mayor Villaraigosa.
"I think in the end it's kind of worth it, so I will, probably I will support it," said Alfredo Hernandez.
The measure must still be approved by the L.A. County Board of Supervisors before it can be put on the ballot.