Many of the most interesting roads in the United States run vertically through the country, and these old national highways offer authentic journeys of discovery and adventure.

Go west, young man! This historic cliché still resonates when it comes to road trips. But whether it is bombing to San Francisco’s Bay Area along the often dull-as-dirt I-80 or trying to find traces of iconic Route 66 amid a tangle of bland interstates, the old paradigm of thinking horizontal when planning a road trip is simply not the way to go.

Many of the best and most interesting roads in the United States run north to south, crossing the nation’s striations and taking you from northern weather and cultures to entirely different ones down south. As a bonus, these roads pack a lot into routes that are often shorter than the east to west standbys. For example, New York to San Francisco is about 2,900 miles by the most direct route, the snoozy I-80. But Chicago to Miami on the legendary US 41 through Memphis is only 1,400 miles -- and a thrilling journey from start to finish.

Often overlooked, the old national highways (those with route numbers proceeded by “US”) offer some incredible north-south journeys. At times the routes disappear under modern interstates but these are mere interruptions in authentic journeys of discovery and adventure. Here are some favourites.

US 1 (2,400 miles)
One of the great American road trips, this fabled route starts at the Canadian border in Maine and goes all the way south to the tip of the nation in Key West, Florida. Along the way it traverses 15 states, including 12 of the original 13 colonies. It hugs Connecticut’s shore, razors across New York City, crosses Washington DC and hits the old south at Richmond, Virginia. Its rural meanderings in Georgia pass towns that have changed little in decades before it joins the balmy Atlantic coast in Florida and follows the beaches all the way through Miami and on to the Keys.

US 41 (2,000 miles)
From the tip of Michigan‘s Upper Peninsula, where Lakes Superior and Michigan bracket the road, US 41 follows the latter lake down the coast of Wisconsin and into Chicago. There it veers southeast and wanders through the dense woods of Indiana and Kentucky, which abound in pioneer sites, especially ones linked to Abraham Lincoln. In Tennessee, the highlight is Nashville, the music city, before the road bounces down to Atlanta. In Florida, US 41 links the resort towns of the Gulf Coast before cutting due east through the heart of the Everglades to Miami.

US 61 (1,400 miles)
From the lake-dotted prairies just north of Minneapolis-St Paul, US 61 follows the Mississippi River through Wisconsin, Iowa and Missouri, where it passes through Mark Twain country in Hannibal and the urban pleasures of St Louis. Continuing south through rural Arkansas and Tennessee, the route earns its legendary moniker “the Blues Highway” as it follows the sinuous course of the mighty Mississippi through its namesake state’s Delta Region. Crossing into Louisiana, US 41 ends fittingly at the blues clubs and other myriad pleasures of New Orleans.

US 83 (1,900 miles)
The sleeper of great US roads, US 83 is anything but a snooze, especially if you want hundreds of miles of driving through wide-open spaces, little changed since the last Conestoga wagon passed through. From Manitoba to Mexico, the route runs near-arrow-straight south through North and South Dakota, Nebraska, Kansas and Oklahoma. The skies are big, the vistas wide and the small towns offer respite from chain-filled interstate interchanges. In Texas, the beautiful Hill Country is a highlight before the road hits the troubled yet fascinating Mexican border at Laredo and follows the Rio Grande River to Brownsville.

US 89 (1,250 miles)
No US highway hits more iconic national parks than US 89, starting with Glacier near the Canadian border in Montana. Hugging the east side of the Rocky Mountains it passes Yellowstone at the Wyoming border and then drops down behind the iconic Grand Teton. In Utah it passes the mineral-laced waters of the Great Salt Lake and in the south cuts between Zion and Bryce Canyon National Parks. Over the line in Arizona is the biggest spectacle of all, the Grand Canyon. Although US 89 officially ends at Flagstaff, you can follow its original route south through Tucson and Saguaro National Park to Nogales and the Mexican border.

US 101 (1,500 miles)
US 101 is easily one of the most famous American highways. The road starts on the Olympic Peninsula across Puget Sound from Seattle. It then curves around to the Pacific, from which it never strays far all the way south. The views become spectacular at Astoria, Oregon and never diminish as you pass the giant redwoods of northern California right through to San Francisco. Although many people opt for Highway 1 south of here, staying with US 101 takes you through Steinbeck Country and Salinas and on past the historic 17th-century Spanish missions that once lined the El Camino Real. At Paso Robles, hundreds of wineries vie for your attention before the highway encounters the beautiful southern California coast and follows the beaches through Santa Barbara. Further on it picks up the evocative name Hollywood Freeway and ends near downtown Los Angeles.

The article 'America’s best north-south roads' was published in partnership with Lonely Planet.