ATLANTA (AP) — Voters have rejected a penny sales tax referendum to pay for transportation projects in nine of 12 regions in Georgia, including in metro Atlanta, unofficial returns show.

With 94 percent of precincts reporting, 63 percent of metro Atlanta voters rejected the tax, compared to 37 percent in favor.

The penny sales tax to pay for billions in transportation projects over the next decade was a draw for many voters in Tuesday's primary election. The issue was on the primary ballot in 12 districts around the state, with voters in each region deciding whether to levy the tax to pay for road and transit projects in their communities. Statewide approval was not required. The Atlanta region stood the most to gain.

Critics derided the proposal as an unfair tax on the poor that wouldn't deal with the problems of sprawl. Tuesday's vote "shows the power of the people," said Debbie Dooley, Georgia Tea Party Patriots state coordinator and an outspoken opponent of the measure.

"They ran a top-down, PR campaign, whereas we ran a bottom-up, true grassroots political campaign," Dooley said Tuesday. "The people are sending a message, and elected officials would do well to take heed: You aren't getting any more of our tax dollars until you can show you're responsible and can be trusted with the money you have now."

Supporters included Republican Gov. Nathan Deal and Atlanta Mayor Kasim Reed, a Democrat; they were increasingly visible in the days leading up to the vote. They tied the tax to Georgia's economic future and promised the infrastructure projects would ease traffic congestion for frustrated commuters.

Reed, who crisscrossed the city in the final stretch of the campaign, conceded defeat late Tuesday but remained committed to the issue.

"I respect the decision of the voters, but tomorrow I'm going to wake up and work just as hard to change their minds," he told supporters at a rally.

In a statement, Deal also expressed disappointment in the outcome of the vote.

"Given state budget constraints, significant reductions in federal funding and the long time it takes to get projects completed, the rejection of the TSPLOST significantly reduces our capacity to add infrastructure in a timely fashion," the governor said. "This is not the end of the discussion; it's merely a transition point. There's a consensus among Georgians that we need transportation investment, and we must more forward by working with the resources available."

Supporters spent $8 million trying to convince voters that the plan would add jobs, ease congestion and improve the quality of life — making the campaign one of the most expensive in state history.

Critics, who spent far less, blasted the plan as not only the heftiest tax proposal in state history, but as a false strategy that failed to encourage smart growth.

Tea party members, the state NAACP and the Sierra Club comprised an unlikely coalition that opposed the referendum, relying on e-mail and social media to urge voters to defeat the measure.

Steven White cast his ballot in Marietta, and said he voted against the transportation tax because he didn't think the projects would shorten his commute.

"I didn't really see any benefits in voting for it," said White, 29, who added that he felt the plan also did little to improve public transit or address infrastructure needs in the suburbs. "I just threw it back at them. I thought (lawmakers) should come up with a better plan."

Each district decided its own fate, with regions that rejected the plan getting nothing. The Savannah region rejected the transportation tax, 58 percent to 43 percent. The measure also went down across four other north Georgia districts and in the southern, southwest and middle Georgia districts.

The Central Savannah, River Valley and Heart of Georgia districts all approved the measure.

In metro Atlanta, supporters estimated the tax would generate more than $8.4 billion between 2013 and 2022. The 10-county metro Atlanta region stretches from Cherokee to Fayette counties, including Gwinnett, DeKalb, Fulton and Cobb counties — among the state's most populous.

The referendum was years in the making at the legislative level, and many lawmakers touted the choice as one of local control for communities. Regional commissions gathered public input for months before coming up with local project lists of varying scale and budget.