Pan American Highway The longest road in the world is the Pan American Highway which begins in Prudhoe Bay, Alaska, and stretches all the way down to Ushuaia, Argentina. All in all, the road covers 30,000 km (19,000 miles).

The Pan-American Highway remains the largest and longest "road" in the world in 2026, stretching approximately 30,000 kilometers (19,000 miles) from Prudhoe Bay, Alaska, to Ushuaia, Argentina. It is not a single, continuous highway but rather a vast network of interconnected roads that traverses through 14 countries and multiple climate zones, including tundra, rainforests, and high-altitude mountain passes. A notable break in the road is the Darien Gap, a roughly 100-kilometer stretch of dense jungle and swampland between Panama and Colombia where no road exists due to environmental and political concerns. In 2026, travelers attempting this route must bypass the gap via ferry or air. While there are other "wide" or "busy" roads—such as the Katy Freeway in Texas with up to 26 lanes—the Pan-American Highway stands as the global leader in terms of sheer geographical scale, representing one of the most ambitious engineering and diplomatic achievements in human history, connecting nearly the entire length of the North and South American continents.