Expressway Bulletin: Be on the alert for two cop-killers. Dangerous! One believed wounded. It is a sultry July Fourth weekend, and the exodus from New York City has begun. A hundred thousand cars are on the Expressway heading for the ocean shore. Travelers who begin this trip as strangers will meet and enact their private dramas within the closing circle of a police dragnet. There will be joy and pain, terror and triumph, love and death this weekend on the Expressway. Fictional documentary.