MARIETTA - County budget leaders are projecting that revenues from the six-year transportation SPLOST will total $786 million, down five percent from the original 2005 estimate of $826 million.

Voters narrowly approved the penny-on-the-dollar sales tax in September 2005 to pay for improvements to roadways and in public safety, including a new jail expansion. Collections began on Jan. 1, 2006, and are slated to expire on Dec. 31, 2011.

The county is four years into collections for the tax, and the overall estimate includes actual revenues through November 2009. There is about a two-month lag between the time retailers collect the tax and when it is received by the county.

Jim Pehrson, the county's assistant comptroller and budget director, created the revised projections based on retail sales data.

"It's still a forecast, and you never know what the economy is going to do," Pehrson said. "We tried to be conservative in our estimates."

For 2010 and 2011, the county's revised projections are nearly 11 percent below the original estimates for those years. Under the original estimates, the combined collections for the two years were $297 million. The county now expects to bring in $265 million over those two years.

Bob Galante, director of engineering within the county's transportation department, said his agency is proud of its project starts four years into the tax program.

"Eighty-one percent of our projects have been started, with 170 completed through 2009. That's unprecedented. I don't think you'll find any other major transportation departments doing that," Galante said.

Some of the largest projects that were cut because of lowered revenues included improvement plans on Bells Ferry Road, Lower Roswell Road and Windy Hill Road, and six sidewalk projects.

The county's revisions contrast starkly with those of the Cobb School District, which began collections for its five-year SPLOST III on Jan. 1, 2009.

Last week, the school board heard from two noted Kennesaw State University economists, who projected that the schools SPLOST would bring in only $586 million, a 26 percent drop from the original estimate of $800 million.

The county is interested in asking voters to continue the SPLOST program after 2011, though no date has been set for a referendum. Leaders had discussed putting it on the ballot this fall, but Chairman Sam Olens now says "next year is more likely."

Olens said that a potential new SPLOST could fund the purchase of parks land parcels as recommended by the citizen's advisory committee last year. Although voters approved a $40 million bond in 2008, Olens said Thursday that program is "gone" because it would require a tax increase to finance the bond.

News editor Kim Isaza contributed to this report.