Self-driving cars may be here soon, but anyone who's ever driven on an interstate highway through, say, Nevada may already have experience with one. See, any car can be a self-driving car as long as the road is straight enough. So where would you go if you want to find the world's longest perfectly straight road, someplace you could just set the cruise control, sit back, and enjoy the scenery? Well, unfortunately, you won't be enjoying the scenery much, because the world's least exciting roads tend to pass through the world's least exciting landscapes.

In search of the long and un-winding road.

North Dakota likes to brag that state highway 46, running 124 miles from Streeter to Lithia, is perfectly straight. On the map you can see that it does have the occasional jog, like where it crosses the Sheyenne River at Little Yellowstone State Park. But there is a stretch from Little Yellowstone east to the town of Kindred that's over forty miles of completely curveless driving. There are sixty-four miles of unvarying highway along U.S. Route 412 between Hardesty and Slapout, Oklahoma, but that looks a little wobblier on Google Maps, presumably due to slight vagaries of surveying.

The straightest interstate is a dry lake bed in Utah.

There are more than thirty miles of Interstate 80 across the Bonneville Salt Flats in Utah that are straighter than either of those—and flat as a pancake to boot, if you're looking to travel in a straight line in all three dimensions. My favorite thing about this drive is that its only landmark is an 87-foot-tall concrete sculpture called Metaphor: The Tree of Utah. It's true: in this part of Utah, trees are nothing but a metaphor.

At least Utah has one more tree than southern Australia.

I only know of one road in the world that officially advertises its boring-ness: the Eyre Highway across Australia's Nullarbor Plain includes a stretch called the "90-Mile Straight." "Australia's Longest Straight Road, 145.6 km," a sign announces. The Nullarbor Plain lives up to its name, from the Latin for "no trees." The highway is named for John Eyre, the first European to cross the plain, who called it "a hideous anomaly, a blot on the face of Nature, the sort of place one gets into in bad dreams."

But the Saudis win the global "Shortest Distance Between Two Points" award.

All these candidates pale beside Highway 10 in Saudi Arabia, which runs precisely due east from the oil complex of Haradh all the way to a slight bend near the Emirati border. That's 140 miles of straight, hot blacktop, a road the length of Massachusetts where I guess you could lock your steering wheel and climb in the back seat for a nap, if you trusted your alignment enough. Many European and American highway planners have purposely avoided long straightaways, to keep drivers' attention on the road, but in the Arabian Desert, the stakes are lower. There's nothing within twenty miles to hit!

This article has been updated.

Explore the world's oddities every week with Ken Jennings, and check out his book Maphead for more geography trivia.