America's Longest Highway Tunnel (2025)

A remote Alaskan engineering landmark, the Anton Anderson Memorial Tunnel near Whittier is the longest highway tunnel in the United States at about 2.5 miles, considerably longer than the next-largest U.S. tunnel. Finished in 1943 amid World War II, it was built to link the tiny port town of roughly 250 residents to the Alaska Railroad and the Portage Glacier Highway, and it played a strategic role for military logistics. The tunnel is built to endure brutal local conditions - temperatures as low as −40°F and winds up to 150 mph - and remains a vital transportation artery connecting Whittier to Anchorage, roughly an hour and fifteen minutes away.

Operations are unusual and require planning: the single bore alternates traffic direction every 15 minutes, runs on a seasonal daily schedule, and carries both road vehicles and rail. Summer hours run roughly 5:30 a.m. to 11:15 p.m.; winter hours shift later. Round-trip tolls are about $13 for a standard vehicle and $22 for large vehicles or RVs, with special arrangements for oversized loads. Travelers are advised to visit in July-August if possible, equip winter vehicles with four-wheel drive and snow tires, and remain alert through the one-way, limited-exit tunnel. Passing through is presented as both a practical route and a memorable Alaska experience, often paired with wildlife tours, museum visits, and nearby hiking.