U.S. Route 20
U.S. Highway 20 (US 20) is an east–west United States highway that stretches from the Pacific Northwest all the way to New England. The "0" in its route number indicates that US 20 is a coast-to-coast route. Spanning , it is the longest road in the United States, and particularly from Newport, Oregon to Boston, Massachusetts, the route is roughly parallel to that of the newer Interstate 90 (I-90), which is in turn the longest Interstate Highway in the U.S. There is a discontinuity in the official designation of US 20 through Yellowstone National Park, with unnumbered roads used to traverse the park.
Glenn Highway
The longest stretch of freeway in Alaska runs mostly along the Glenn Highway, beginning in north Anchorage, continuing onto the Parks Highway at the interchange of the two roads, and ending in the city limits of Wasilla, for a total of approximately 38 miles (61 km). This portion of the Glenn Highway is the only road access to Anchorage for most of the state (with the exception of the Kenai Peninsula on the Seward Highway), and as such is the main traffic corridor for Anchorage's suburbs in the Chugiak-Eagle River and Mat-Su areas. The highest point on the highway is at "Eureka Summit", which sits on the divide between the Chugach and Talkeetna mountain ranges.