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.
California
The state has been a pioneer in road construction. One of the state's more visible landmarks, the Golden Gate Bridge, was the longest suspension bridge main span in the world at between 1937 (when it opened) and 1964. With its orange paint and panoramic views of the bay, this highway bridge is a popular tourist attraction and also accommodates pedestrians and bicyclists. The San Francisco–Oakland Bay Bridge (often abbreviated the "Bay Bridge"), completed in 1936, transports about 280,000 vehicles per day on two-decks. Its two sections meet at Yerba Buena Island through the world's largest diameter transportation bore tunnel, at wide by high. The Arroyo Seco Parkway, connecting Los Angeles and Pasadena, opened in 1940 as the first freeway in the Western United States. It was later extended south to the Four Level Interchange in downtown Los Angeles, regarded as the first stack interchange ever built.