NAHANT – Traffic congestion on Castle Road should be eased dramatically come September, according to town and school officials.Nahant Town Administrator Mark Cullinan said the site improvement project at Johnson Elementary School, which is expected to be complete before school opens next month, would ease congestion and enhance safety.Cullinan said traffic flow would be much smoother and it would enhance public safety.?We’re working to develop a traffic plan,” he said. “Parents should expect to change their behavior. Some parents have been parking on Castle Road and others have been dropping their kids off in the street. All drop offs and pickups will be on school property. We won’t have kids getting out of cars and crossing the road to get to school.”Cullinan said he is working with Superintendent Joseph Lisi to develop the traffic plan, which utilizes the new one-way loop around the school. Attempts to reach Lisi were unsuccessful on Wednesday, but Cullinan said in September students in pre-kindergarten through second grade would be dropped off near the front entrance to the building and cars would exit using the loop around the school.He said students in the higher grades would be dropped off at the new entrance, which is near the cafeteria.?Parents of students in grades three through six should enter by the Coast Guard Housing,” he said