DURHAM - Durham County voters will be on their own this fall when they consider a half-cent sales tax increase for big improvements in public transit. Regardless of the outcome, the vote will be felt next door in Wake andOrange counties, too.

The tax would generate about $18.4 million a year in Durham to help boost bus service by 25 percent within the first three years and to help launch commuter trains by 2018 and light rail by 2025. State and federal funds also would be sought.

The Durham commissioners voted 5-0 Monday night to schedule referendums for Nov. 8 on the half-cent transit tax and on a separate quarter-cent sales tax for local schools and Durham Tech.

Regional polls have shown stronger voter support for the transit tax - and broader consensus on detailed transit plans - in Durham than in Wake and Orange.

But if the sales tax measure were to fail in Durham this fall, its two neighbors would have to rethink plans for a light-rail line from East Durham to Chapel Hill in Orange County and for rush-hour commuter trains from West Durham to Garner in Wake County.

"We're in the center of the region," Ellen Reckhow, a Durham County commissioner, said Tuesday. "Part of the rationale for us going first is that if it passes, the good news for either of our neighbors is they know they would have a partner."

An electoral victory in Durham County could add political luster to the cause in Wake and Orange.

"We hope to put it on the ballot next year, so certainly it would help if it already has had success and people are talking about it in a positive way," said Barry Jacobs, an Orange County commissioner.

While the Orange commissioners aren't ready for a half-cent transit vote this fall, they're pushing ahead with a November vote on a separate quarter-cent sales tax increase.

Wake County officials are still discussing bus-and-rail priorities with leaders of 12 municipalities, with a referendum possible in November 2012. Commissioners have no appetite for any kind of tax increase this year.

"With unemployment continuing to be stubbornly high and the economy not doing well, asking for additional tax revenues in this environment is not where most people are heading," said Joe Bryan, a Wake commissioner. "That is not the playing field in Wake County."

Calculations in Durham

Durham commissioners cited different calculations that made 2011 more auspicious for their transit tax vote.

The county faces a likely property tax increase in 2012, but not this year. And commissioners hope local voters find it easier to swallow a combined three-quarter-cent sales tax increase shortly after a 1-cent drop in the statewide sales tax, which will take effect Friday.

Still, Commissioner Joe Bowser was uneasy about asking Durham voters to go first, while their neighbors watch from the sidelines.

"Now if Wake County and Orange County had approved it at this point, I don't think you would have much argument because we would be the piece that was left out of the puzzle," Bowser said Monday. "But right now, we are the only piece that is trying to get into the puzzle - and we don't know what they are going to do."

So if Durham County voters approve the transit sales tax in November, they won't be asked to start paying the tax right away.

The Durham commissioners said they will wait to see what happens in Orange and Wake in 2012 before they authorize Triangle Transit, a three-county public agency that is leading the regional planning effort, to begin collecting the tax in Durham County.

Against the tax

John Hood, a critic of regional transit plans, said it's hard to predict what Durham voters will do with the half-cent transit tax proposal.

"Certainly around the country, even in difficult times, there have been some transit taxes passed," said Hood, president of the Raleigh-based John Locke Foundation, which advocates for tax cuts and smaller government. "People are worried about traffic congestion. They want to see something done about it - although I don't think the system they're proposing for the Triangle will have any effect on congestion."

Correspondent Virginia Bridges contributed

to this report.