A multimillion-dollar campaign to woo voters into passing the biggest single infusion of infrastructure dollars in metro Atlanta in at least 40 years is under way. Expect a quiet launch against noisy opposition.

Local governments last week approved a list of more than $6 billion worth of transportation projects across 10 counties. The list of projects, a mix of road projects and public transportation fixes, is aimed at reducing congestion and making commuting easier for more than 800,000 metro Atlantans.

But voters know little to nothing about the high-stakes transportation sales tax that would pay for the projects, according to a poll commissioned by The Atlanta Journal-Constitution and Channel 2 Action News. Nearly half said they are either undecided or against the proposal to add a 1-cent sales tax.

For those reasons, a team of strategists, fundraisers and communication experts aren’t starting the pro-transportation tax campaign with a splash.

Instead, they will spend the next few months building upon “education” efforts: Talking to whoever will listen about the project list, explaining what it is and what it aims to do for commuters in specific locations. They will then shift into outright advocacy — campaigning door-to-door and launching television and radio ads — starting next year.

The approach aims to build momentum going into the July 31 primary, when voters in metro Atlanta’s 10 core counties will be asked to approve the 10-year, 1-cent sales tax.

“Sometimes the community knows it needs to take a step of its own future,” said Kevin Ross, a strategist for the privately funded public awareness campaign that expects to spend more than $6 million selling the referendum.

The campaign team, however, must still prove it can overcome an early — and glaring — stumble that saw one of its key strategists quit. And it faces vocal opponents who have been hammering away at the referendum for months, lacing their arguable head-start with a popular theme: no new taxes.

The Atlanta Tea Party has already pledged to focus on defeating the referendum, with the Georgia Tea Party assisting in other regions across the state deciding their own transportation referendums. A metro tea party task force launched efforts over the weekend, including a new website to get its message out.

“We want this thing to be extremely balanced,” said Bob Frey, who is helping coordinate the task force. “We’re not against transportation. We’re not against taxes. We’re against being taxed for the wrong reasons.”

Tea party leaders do not think the project list will benefit the majority of residents in areas where they need the most relief, saying it is otherwise too expensive and unwieldy.

They scored a notable victory in August, when the tea party joined several groups in defeating an effort by Gov. Nathan Deal to hold next year’s transportation referendums in November instead of July — a move that would have given proponents, including Deal, more time and a larger pool of voters to work with.

Still, metro business leaders are so concerned about congestion blocking economic growth that they are helping to pay for the campaign to pass the tax. Nearly 80 businesses and community organizations have begun to meet regularly to provide input and support to the effort — campaigners call them their “First Friday” support group, because that’s the day the group usually meets.

They hired Ross, an Atlanta-based Democratic strategist and lawyer, last month after the departure of Virginia-based Glenn Totten. Totten is a nationally recognized political strategist who helped get Georgia a lottery two decades ago. He said when he left in August that he did not have enough time to devote to the campaign, although the move was deemed “mutually agreeable” by others on the team.

Ross’ hiring now gives the campaign decidedly local leadership, including Paul Bennecke, a consultant who has had leadership roles in the Republican Governors Association, the Georgia Republican Party and the 2002 campaign for former Gov. Sonny Perdue. National pollster David B. Hill is providing polling and research to the campaign.

It also provides to the campaign someone who has at least some experience with local sales tax campaigns. In 1994, Ross helped get voters to support a $150 million bond issue for pre-Olympic repairs to Atlanta’s streets, parks, bridges and sewers. Three years later, he helped sell a 1 percent sales tax to pay for $470 million in construction and renovation costs for Atlanta city schools.

In an interview last week, Ross said he sees similarities with the school construction campaign, which passed by a wide margin because the public recognized the problem of how best to build and maintain its schools.

In the AJC-Channel 2 Action News poll, 91 percent of metro voters said it was important to address the region’s transportation problems to improve its quality of life and economic future. The transportation campaign will likely hone in on that sentiment, stressing local projects aimed at easing the region’s gridlock.

“We need,” Ross said, “to make an investment to make it better.”