Voter approval of Measure J could provide $90 million in additional tax revenue for transportation projects. (Mark Hogan/Flickr)

If approved at the ballot box, Measure J would tack on an additional 30 years to a sales tax for transportation projects set to expire in 2039. The measure, which requires approval of two-thirds of voters to pass, would generate an extra $90 billion in local sales tax revenue until 2069.

Measure J, supported by L.A. Mayor Antonio Villaraigosa, in addition to several business, environmental and labor groups, would accelerate projects such as the Green Line extension into the South Bay, Gold Line extension into the San Gabriel Valley, the Westside Subway extension and the Regional Connector.

However, some unions argued that Metro's growing emphasis on rail has come at the expense of the county's bus system.

"[The measure] is going to benefit large real-estate and construction corporations, while impacting communities of color, especially bus riders who are going to see cuts in their service and fare increases," said Sun-Young Yang, lead organizer of the Los Angeles Bus Riders Union.

Yang contended that despite the additional funds for transportation created by voter-backed Measure R in 2008, Metro has scaled back on its bus service. She said the discontinuation of Metro Line 305, which provided commuters a direct route from South L.A. to West L.A., has "led to further financial burden" for working-class riders.

"After that line got eliminated, many of the domestic workers from South L.A. that worked on the Westside now have to transfer three times to get to their low-wage jobs," Yang said.

Those who oppose extending the sales tax are attempting to inform voters on the issue through the No on Measure J Web site. In addition to the Bus Riders Union, the Crenshaw Subway Coalition and the Beverly Hills Unified School District have also come out against the measure. 

But the measure's supporters claimed that a 'Yes' vote would create 400,000 new county jobs and provide necessary resources to invest in infrastructure improvements such as road repair.

"No matter what your politics, everyone benefits from traffic relief and putting people to work," said Matt Szabo, executive director of the Yes on J campaign. "Our hope is to allow those currently paying the transportation tax to actually realize the benefit of that tax by having the projects built within a reasonable amount of time."

Measure J has secured the endorsements of area newspapers like the L.A. Times and Daily News. Supporters have also ran television and radio advertisements to boost support for the initiative. Szabo said backers hope to secure more endorsements from local Chambers of Commerce and neighborhood groups in the week ahead.

Opponents said "it is a tough fight" going up against a campaign that has more than $2 million at its disposal thanks to donations from financial heavyweights like Anschutz Entertainment Group and Museum Associates, a nonprofit that operates the L.A. County Museum of Art, but the phone-banking will continue until Election Day nonetheless.

"We have a tiny, but formidable operation," Yang said. "We're up against a multi-million dollar, corporate-backed campaign. Hopefully we'll be able to swing 34 percent of the vote to defeat this measure."

Read more Neon Tommy stories on public transportation and the 2012 election.

Reach Senior Staff Reporter Danny Lee here; follow him on Twitter here.