Alfred Hitchcock could not have conjured a scarier highway—122 miles of vertigo between Monterey and Morro Bay. Two lanes for nearly its entire length, the road meanders along cliff tops poised high above the Pacific, including 33 bridges and countless drop offs into liquid oblivion. Anyone faintly squeamish should not attempt to drive this route. 

For more information: Highway One/Big Sur

The Big Islands’ incredible Saddle Road shoots between two hulking volcanoes across a sweltering lava-rock desert. “Famously bad and dangerous” is how one guide describes Hawaii Route 200 between Hilo and Waimea. Although improved in recent years, much of the route is narrow and one-way; intermittent fog makes it even more hazardous. Side roads lead to the summits of Mauna Kea and Mauna Loa.

For more information: The Saddle Road

The 187-mile drive from Aspen to Pueblo traverses some of the highest, harshest and most desolate geography in North America. The drive kicks off with a summit of 12,095-foot Independence Pass, a stretch of state highway 82 that is narrow, twisting and often without guardrails. The latter portion near Cañon City includes a short detour across Royal Gorge Bridge, which hovers 1,053 feet above the Arkansas River—built 1929 and still the highest suspension bridge in the world.

For more information: Independence Pass

The longest stretch of road in U.S. with no services, the 414-mile Dalton throws down several gauntlets including gravel roadway, steep grades, dangerous animals, and dire weather conditions. It’s an awful long wait for a tow if you break down out here.

For more information: Dalton Highway

They call it the “loneliest road” in America, the 473 miles of U.S. 50 between Hinckley, Utah and Carson City, Nevada. But it’s also one of the creepiest, especially in mid-winter when snow can cover the entire route or the middle of summer when daytime temperatures are almost always in the triple digits. The Nevada Commission on Tourism issues a free “Highway 50 Survival Guide.”

For more information: Travel Nevada
 

Tucked just below Great Smoky Mountain National Park, the sinuous “Tail of the Dragon” is an 11-mile stretch of U.S. Highway 129 between Tabcat Bridge (Tenn.) and Deals Gap (N.C.). Get ready for 318 curves, many of them monster switchbacks and hairpins, as well as a series of steep “S” curves called The Slide.

Formore information: Tail of the Dragon

This rollercoaster desert road along the Rio Grande is straight out of No Country for Old Men (which was filmed nearby). A dipsy-do roadway, stray animals and floods are just a few of the hazards along the 99 miles of the river road between Lajitas and Candelaria. Much of the highway runs through picturesque Big Bend Ranch State Park.

For more information: State Highway 170

One of the holy grails of American motorcycle touring, Route 16 runs north-south between Middlebourne and Grundy through the heart of West Virginia. Switchbacks, hairpins, potholes and narrow portions mean that drivers can never be on auto pilot. More than 50 miles of the south-central stretch of Highway 16 is part of the Coal Heritage Trail through the depths of Appalachia.

For more information: State Route 16

Completed in 1936, the 69-mile Beartooth is the highest highway in the northern Rockies and one of the highest in the entire nation. It twists through a high mountain landscape of montane glaciers, alpine meadows and more than 20 peaks higher than 12,000 feet. During the depth of winter, the snow-covered route is accessible only by ski, snowshoe and snowmobile.

For more information: Beartooth Highway

Named after a Spanish term for the Pueblo Indians (“mokee”) who once lived in this area, the Moki Dugway is a spectacular switchback stretch of State Highway 261 in southern Utah. Plunging off Cedar Mesa, the narrow gravel road drops 1,100 feet in just three miles as it snakes its way down into the Valley of the Gods. Moki Dugway is part of the “Trail of the Ancients” National Scenic Byway.

For more information: Moki Dugway

The scariest route of all may be Interstate-15 between California’s Cajon Pass (near Los Angeles) and Las Vegas. The route isn’t especially twisty or desolate road, yet it’s the deadliest stretch of interstate in the entire nation, especially after dark when people are racing back and forth between L.A. and Vegas. According to the Insurance Institute of Highway Safety, 173 crash-related deaths occurred on this 207-mile stretch of interstate during one recent five-year period.