Here we are, Gwinnett.

The county has adopted an ambitious transit development plan, one that may pave the way for heavy rail all the way from Doraville to Gwinnett Place and includes other improvements like bus rapid transit and expanded local bus service. The next step is for the county commission to call for a referendum — but what would be its aim? When would it happen? Does it matter?

Below, The Atlanta Journal-Constitution provides answers to those frequently asked questions and clarifies other aspects of the often muddled process.

What exactly are we (potentially) voting on? If and when a referendum is held, Gwinnett residents will be voting on whether or not they want to pay a new one-cent sales tax for the next 30 years. The money would fund transit and transit alone. Such a sales tax would raise an estimated $5 billion or more, though projections become less clear the further into the future you get.

The approval of the sales tax would effectively give the county the go-ahead to execute its recently adopted transit development plan.

So…what would the difference be between a November referendum and one held in 2019 or later? Aside from the literal timing — some have encouraged Gwinnett to go ahead and strike while the iron is hot — the difference is the level of MARTA's involvement with Gwinnett's overall transit future.

The ATL, the regional transit agency created by legislation that passed earlier this year, does not go live until Jan. 1. Gwinnett can't vote on joining it before then.

A November referendum, then, would involve making MARTA the administrator of the sales tax revenue raised by Gwinnett. County Commission Chairman Charlotte Nash recently described the potential arrangement as “a transit tax that would be spent through a contract with MARTA.”

If a referendum were held in 2019 or later, The ATL could get involved. It would have to approve projects proposed by Gwinnett (or any other member) before the county moves forward.

This could be an important distinction for voters, given Gwinnett’s historic reticence not only toward transit but MARTA specifically.

That said, Gwinnett would likely end up having to contract with MARTA in one way or another — House Bill 930 names it the sole provider of any new heavy rail service in the 13-county ATL region.

(Clarification: The option for a referendum on a sales tax imposed through the MARTA Act doesn’t disappear after Jan. 1. Gwinnett could, theoretically, hold such a vote even after The ATL is formed.)

So MARTA would be in charge? It ultimately would depend on how a contract was written. But yeah, sort of.

If a November referendum is successful, MARTA would have a say in how the money is spent, though Nash recently said she was confident the agency would roll with what Gwinnett already has planned.

Neither the county nor MARTA have publicly commented about a potential contract.

When will the decision on timing be made? Legislation technically allows the county to wait until 30 days before the Nov. 6 election to call a referendum. Nash has said that, practically-speaking, in terms of the literal process of getting it on the ballot, the call would need to be made in August.

Presumably, MARTA’s Board of Directors would approve the contract before the county takes formal action on it.

That group’s next meeting is Aug. 2.

So they're definitely calling a referendum at some point? Definitely is a strong word.

But that said, two of four district commissioners (Jace Brooks and Lynette Howard) have already expressed strong support for the idea (and for it to happen in November, as long as a suitable contract is worked out with MARTA). Nash’s presumed vote would make a majority, even if the remaining two district commissioners (Tommy Hunter and John Heard) remain question marks.

Heard has expressed support for transit expansion but hesitance at involving MARTA more than necessary.

Hunter’s thoughts are largely unknown. He represents one of the most rural parts of the county.

What are the odds of a referendum passing? Well…who knows, really. But according to the county's transit study — which involved multiple rounds of public input — a sizable majority of residents are in favor of increasing transit offerings. Most folks were also willing to pay for it via a new sales tax, according to the study.

There was very little, if any, opposition at the public meetings held during the transit planning process. No organized opposition movement has formed.