If a transportation tax passes in a 2012 referendum, Cobb and Douglas counties want it to fund the interchange at I-285 and Bolton Road, even though that's in the city of Atlanta.

A regional call center to coordinate rides for disabled and elderly passengers wouldn't be located just in one town. But Fayetteville, Decatur and Cherokee and Clayton counties have all requested that such a center get a shot at funding from the referendum.

The Atlanta region's cities, counties and towns may well end up fighting each other this summer for slots on the referendum's project list, to be finalized in October. But for now, as local wish lists are tallied, they are backing each other up to the tune of billions of dollars' worth of projects.

When regional officials did a rough total adding up the local wish lists as they rolled in last week, they came up with $24 billion. But so many local governments put in additional notes of support for projects outside their borders that the latest dollar total for all the region's desired projects now shows up at $29 billion, according to the Atlanta Regional Commission. That number is still subject to change as planners dig into the lists.

"It’s a good sign," said Chick Krautler, director of the ARC. "I think the whole process of getting these projects put together and submitted has been very, very cooperative and much more coordinated than perhaps most of us thought it might be."

ARC will hand over the entire preliminary wish list to the state's transportation planning director without deleting any projects. The state planning director will then weed out projects that don't meet established guidelines.

Projects must serve a regional purpose, not just a local one. And they should be located within the 10-county region. For example, although widening Ga. 20 in Forsyth County is important to Atlanta suburbs and was requested, Krautler said, Atlanta's tax likely can't pay for it.

About June 1, the state transportation planning director will hand the pool of eligible projects back to the region, where a panel of 21 local elected officials will whittle it down to a final affordable list for the 2012 ballot. Voters will vote up or down on the list of projects in the 10-county region and a 1 percent regional sales tax to fund them.

Whether the final figure for this spring's wish list winds up $29 billion or not, it seems clear it is many times too big for the available money from the referendum's tax.  The dollar limit for the final list will be set in June, but estimates now are in the $8 billion range.

Many factors went into the increase from $24 billion to $29 billion. ARC has weeded out duplicate projects, added projects from supplementary letters of support and found hidden extra costs in project requests.

Referendum 2012

Would a new burst of transportation funding ease your commute and reshape your region? Or would a regional 1 percent tax to generate the money be one tax too many? As voters approach a referendum on regional transportation projects and the tax to pay for them, The Atlanta Journal-Constitution will follow the story with in-depth coverage you won't find anywhere else.