What is the longest north -south highways in the US?

The longest north-south highway in the United States is U.S. Route 1, which stretches approximately 2,369 miles from Key West, Florida, in the south to Houlton, Maine, at the Canadian border in the north. This scenic route runs along the East Coast, passing through numerous states and major cities. Another notable north-south highway is Interstate 95 (I-95), which also runs along the East Coast but primarily serves as an interstate route.