Route 66 vs Utah Mighty 5

Route 66 is the great American road trip: roughly 2,400 miles of the Mother Road from downtown Chicago to the Pacific at Santa Monica, crossing eight states and three time zones. This Chicago to Santa Monica itinerary packs it into 10 days, which is fast. Expect about 200 to 330 miles and five to seven hours behind the wheel most days, mixing interstate stretches with the best surviving original alignments; two to three weeks is ideal if you can spare it. Start with a photo at the Begin sign, then roll past Illinois giants, the bent Chain of Rocks Bridge over the Mississippi and Ozark frozen custard stands. Cross the short Kansas corner and Oklahoma's diners before painting your own stripe at Cadillac Ranch outside Amarillo. In New Mexico, sleep under the glowing neon of the Blue Swallow Motel in Tucumcari, then drive through the badlands of Petrified Forest National Park, the only national park that protects a stretch of Route 66. A day off the road from Williams takes you to the Grand Canyon's South Rim. The finale climbs over the Black Mountains to Oatman, crosses the Mojave and ends with a sunset at the Santa Monica Pier. Book classic motels ahead in spring and fall.

Utah's Mighty 5 is the classic Southwest road trip: five national parks strung across roughly 400 miles of red-rock desert, each completely different from the last. Start in Zion, where the Virgin River has carved a sheer sandstone canyon you explore by shuttle, then climb to Bryce Canyon's amphitheaters of orange hoodoos at more than 8,000 feet. Scenic Byway 12, one of the most beautiful drives in the country, carries you to Capitol Reef, a quieter park of cliffs, petroglyphs and pioneer orchards near the small town of Torrey. The trip ends in Moab, base for Arches and its 2,000-plus stone arches and for Canyonlands, where the Island in the Sky mesa looks down on the Colorado and Green rivers. Most travelers fly into Las Vegas or Salt Lake City, rent a car and spend about a week, sleeping in Springdale, Bryce or Tropic, Torrey and Moab. Plan ahead: Arches uses a timed-entry system in its busy season, Angels Landing needs a permit, and summer afternoons regularly top 100°F (38°C), so early starts, plenty of water and spring or fall dates make the biggest difference.