title: U.S. Route 101
context: The nearly 1,550-mile-long (2,500km) highway's northern terminus is in Tumwater, Washington: the route remains along the Olympic Peninsula's coastal perimeter west, north, and east; the northernmost point on the highway is in Port Angeles. The southern terminus of US101 is in Los Angeles at the East Los Angeles Interchange, the world's busiest freeway interchange.[2]
question: How long is U.S. Route 101?
answers: nearly 1,550-mile