What is the number of the US interstate highway on which you can drive from New York City to San Francisco?

Spanning nearly 2,900 miles, Interstate 80 is the second-longest interstate highway in the United States and serves as a critical transcontinental artery connecting New York City and San Francisco. Designated in 1956 as one of the original routes of the Interstate Highway System, its final segment was completed in 1986. This modern marvel of engineering closely follows several historic pathways, including the Lincoln Highway, which was the first automobile road to cross the country.

The route of I-80 is steeped in American history, tracing the paths of the California Trail and the Oregon Trail across vast stretches of the West. It also follows the general corridor of the first transcontinental railroad, a testament to the enduring importance of this east-west passage. From the bustling metropolises of the coasts to the wide-open spaces of the Great (Review) Plains and the rugged mountains of the West, I-80 offers a diverse cross-section of the American landscape. The highway passes through 11 states, including major cities like Chicago, Salt Lake City, and Sacramento.

Construction of I-80 was a monumental undertaking that took three decades to complete. The final piece of the highway was laid near Salt Lake City, Utah, an event that marked a significant milestone in the development of the nation's infrastructure. Today, I-80 continues to be a vital corridor for commerce and travel, carrying a steady stream of trucks and passenger vehicles across the country. Its long, straight stretches, particularly in Nebraska and across the Bonneville Salt Flats in Utah, are a notable feature for long-distance drivers.