A group of state lawmakers who oppose the July 31 transportation tax referendum vowed Tuesday to begin work immediately after the vote to prepare another, better solution to the region's traffic woes.

Senate Majority Leader Chip Rogers, R-Woodstock, led a group of five legislators in urging voters to reject the referendum, which would create a 1-cent sales tax to fund transportation projects across Metro Atlanta.

The problem, Rogers and others said, is that the proposed project list would not do enough to ease congestion.

"If voters are going to have this money taken from them, it needs to be for a purpose that ends in success," Rogers said.

State Rep. Ed Setzler, R-Acworth, said the law that created the July 31 referendum allows for the same question to be put before voters again in 2014 should this month's vote fail. In that time, Setzler said, the roundtable of local leaders who created the current project list could work to create a new list that would better address the region's traffic needs.

"I am focused on solving the traffic problems in Atlanta," Setzler said. "This project list doesn't do that."

But supporters of this year's referendum and its project list say it's not that simple. The Atlanta Regional Commission said if this year's vote fails, the Legislature would have to pass a new law in 2013 to begin the process again and that six counties would have to approve resolutions to put the question before voters.

In addition, the law that created the referendum says the earliest a new vote could take place is on a statewide general primary election on or after July 31, 2004. Most state primary elections are earlier in the summer. That means it would likely be 2016 before voters could again decide.

"The opponents have had plenty of time to come up with alternatives, and all they can come up with is 'trust us and we'll do better,'" Untie Atlanta campaign manager Che Watkins said. "Politicians are the ones who have delayed and delayed and let traffic congestion hurt our economy and steal time from our families, and now they are asking us for further delays. Our plan is definitive, it lists the projects that will built, and puts the power in the hands of the voters instead of politicians."