Georgia voters (today) will be asked to decide on a proposed 10-year, 1-cent regional sales tax for transportation. If approved in all 12 regions, it will raise some $18.7 billion statewide.

The idea — and it is a good one — is to develop Georgia’s transportation infrastructure closer to the local level, as opposed to having projects and priorities decided in the state Capitol and the Department of Transportation. Transportation Board veteran Sam Wellborn of Columbus, a staunch supporter of the tax and somebody who has forgotten more about transportation in Georgia than most people will ever know, notes that gasoline tax revenues and federal money are both down, and there is no general fund money to spare.

Georgia is forced to spend ever more on maintenance and less on new projects — obviously a dead-end road. But this TSPLOST is, in our view, a deeply flawed plan. The all-or-nothing formula holds a county, especially a small one, hostage to those around it. If one county votes against the T-SPLOST but the region approves it, the people of that county still have to pay. If a county supports it but the region defeats it, that county loses its share of funding and projects.

There is also the fact, undisputed even by supporters of the TSPLOST, that Muscogee would be a “donor” county: According to a Columbus State University study, taxpayers here would get about $259 million worth of transportation improvement for about $291 million in sales tax. Even that red-numbers math wouldn’t be a clincher if there were a clearer case for both regional and local benefit.

Every sales tax campaign includes a reminder of how much money comes from non-residents. That’s a windfall for a destination city like Atlanta or a tourist magnet like Savannah. It’s even great for Columbus — when the sales tax is mostly or wholly for the benefit of Columbus.

But Columbus anchors the poorest region in the state. Evidence of what will be better 10 years from now if we pass this tax, or what will be substantially worse if we don’t, is at best dubious. (The long-anticipated BRAC benefits come readily to mind.)

The subject of poverty brings us back to the tax itself. Sales taxes take the heaviest toll on low-income working families. It isn’t just Columbus that stands to lose more than it gains; if the projected benefit to southwest Georgia doesn’t materialize, this tax will have been a burden without a benefit, in an area that can least afford it.

Here in Columbus, the TSPLOST would raise the combined sales tax to 8 percent, at least until the school SPLOST expires in 2015. That’s a hefty figure that reduces the city’s appeal to shoppers from out of town … supposedly one of the arguments for the tax in the first place. It could also cripple local efforts to raise future revenue. Muscogee relies heavily on consumption taxes, a reliance long exacerbated by the assessment freeze. The likelihood of sales tax fatigue is just one of many reasons the idea of being locked into this tax for 10 years should give every voter pause.

We don’t buy the repeated implication that raising transportation money this way, at this time, in this economy is our last and only chance. Voters should send this one back to the proverbial drawing board.