A Norcross firm developing a transportation master plan for Gainesville is suggesting ways to address Green Street’s traffic woes without a roundabout, widening the road or banning left turns. Instead, Pond & Co. is recommending a configuration of “unbalanced lanes” — one lane for southbound traffic, two lanes for northbound traffic and a center turn lane. “That’s taking those left-turning vehicles out of the through lanes,” said Daniel Studdard, a Pond planner, at a transportation focus group meeting Thursday night at the Fair Street Neighborhood Center.