The work will be suspended for next week's Thanksgiving holiday from noon Wednesday to 10 p.m. Sunday.
The paving project involves Route 347 in Smithtown between Route 454 and Route 111. It should be done by Nov. 30, the agency said. In the spring the state will add an information kiosk, a small park and a sump.
The Route 347 paving work is scheduled to be finished first, followed by the paving of Route 111 from Sherbrooke Drive south to Hauppauge High School.
The paving of Route 347 and part of Route 111, which intersects it, will be done at night with traffic reduced to a single lane in each direction, the state said.
During the nights when work is scheduled, a westbound lane of Route 347 will be closed from 6 p.m. to 5 a.m. and an eastbound lane from 7:30 p.m. to 6:30 a.m.
Work on Route 111 is scheduled for 10 p.m. to 5 a.m., also with a single lane closure in each direction.