The Perimeter Community Improvement Districts, self-taxing business districts that raise seed money for transportation improvements in the northern Perimeter area, have voted to focus on the interchange at Ga. 400 and I-285. The CIDs would decide on specific contributions toward the $450 million project later, in negotiations with the state, its leaders said. After the T-SPLOST referendum failed, Gov. Nathan deal announced that with limited funding, that interchange was his priority.