Alaska's 2.5-Mile Whittier Tunnel Is America's Longest—and One of Its Most Dangerous
America's Longest Highway Tunnel (2025)
The Anton Anderson Memorial Tunnel in Whittier, Alaska, stretches 2.5 miles, making it the longest highway tunnel in the U.S. Built during World War II and opened in 1943, it withstands brutal winters with temperatures dropping to minus 40 degrees Fahrenheit and winds up to 150 mph. The one-way tunnel alternates traffic direction every 15 minutes and charges $13 for a standard round trip. For a safe visit, travelers should go in July or August and use a four-wheel-drive vehicle with snow tires.
During the winter, temperatures can dip as low as minus 40 degrees Fahrenheit in and around Whittier, and wind speeds can reach a staggering 150 miles per hour, making even a routine journey in this area a treacherous gamble.