A few years ago we considered the claim of Baldwin Street, in Dunedin, New Zealand, to be the steepest street in the world. The Guinness Book of World Records backs Baldwin Street; Pittsburgh protested loudly, since a short stretch of its Canton Avenue appears to be even steeper. Well, let's meet a new aspirant to the World's Steepest Road title: Hawaii's Waipio Valley Road.
• The Waipio Valley, on the north shore of Hawaii's Big Island, is a place of unearthly beauty. This lush, narrow paradise is a sacred spot to many Hawaiians and was the boyhood home of Kamehameha I, the islands' first king. Today visitors marvel at the valley's waterfalls (including Hiilawe, by some accounts the tallest in Hawaii), its wild horses, its empty black-sand beaches.
• The beaches are empty for one very good reason: it's very, very difficult to get down to them. Waipio Valley Road is marked at the beach overlook with the same black diamond usually seen on the world's most dangerous ski slopes. Only cars with very tough four wheel-drive and very confident drivers should try to tackle the precipitous drops and hairpin turns leading to the bottom.
• Many drivers—even ones with 4WD—find that they wear through their brakes on the way down, or stall trying to get back up. One traveler reports that there's only one tow company on the island with a truck that can make it back up the road to the overlook, so you might be paying a pretty penny if you decide to risk violating your rental car agreement in Waipio.
• Data visualization scientist Stephen Von Worley surveyed the valley during a recent visit and found that Waipio Valley Road has long sections with a 30% grade. At times, the road drops away at a 39% grade, which would make it (briefly) steeper than anything in the hills of Dunedin or Pittsburgh. But Von Worley thinks he's found an even steeper stretch elsewhere: the top of Bradford Street, in the San Francisco neighborhood of Bernal Heights. A newly paved section of Bradford Street boasts an amazing 41 percent grade, enough to propel a car from zero to sixty in just 7.2 seconds, through gravity alone! May God have mercy on your clutch.
Explore the world's oddities every week with Ken Jennings, and check out his book Maphead for more geography trivia.
