Gwinnett County transportation officials are proposing a heavy rail transit line for the first time. The county has rejected MARTA expansion twice in its history.

Alan Chapman, the county director of transportation, said there has been a change of heart among Gwinnett residents.

“I think, in general, the support for transit has grown in Gwinnett over the last several years.”

“Our population has grown, and I think we have more traffic congestion than we’ve had in the past, and I think our citizens recognize that we need really to address every mode,” he said.

Gwinnett County’s population has more than doubled since 1990.

The new Gwinnett transit proposal includes adding 4 to 5 miles of heavy rail from the Doraville MARTA station to Norcross. Bus rapid transit will be added for routes past Norcross.

Chapman also said recent state legislation that allows metro Atlanta counties to raise money for transit has made heavy rail financially viable. It costs about $250 million per mile to build heavy rail, versus $25 million to $30 million for bus rapid transit.

Chairman of the Gwinnett County Board of Commissioners Charlotte Nash said although the future of heavy rail “may be limited” in Gwinnett, extending it to Norcross will be useful to get riders across I-285 without traffic and without a transfer.

The proposal, which has been nearly a year in the making, is not finalized yet. The public will have six opportunities to offer feedback on it in person, beginning Saturday.