The Steepest Street In The World? It’s Surprisingly Controversial

It’s difficult to know for sure, since, well, not all of them have been officially logged. Perhaps the easiest slopes to measure, though, are the ones that, well, have already been measured – that is, the ones in inhabited places. As it turns out, there are quite a few places that would like to claim the title of “world’s steepest street” – so who takes the top spot?

The steepest street in the world: a contentious issue

The official title of the “steepest street” is actually quite controversial: the associated Guinness World Record has changed hands between two different places multiple times, and there seems to be a (mostly) playful rivalry between the towns that host the streets in question.

Luckily, the two places will never come to blows, since they’re pretty much as far away from each other as possible. Back before 2019, the title was held by Baldwin Street in Dunedin, New Zealand, thanks to a confirmed gradient of 34.97 percent. That’s enough to make it a bona fide tourist attraction, with sightseers coming from thousands of miles around – well, it is New Zealand, they kind of have no choice – just to lie on the ground and take forced-perspective souvenir photos.

But you’ll notice we said “before 2019” – because that’s the year it all went wrong for Dunedin.

“I first realized this street was a contender for the steepest street in the world when my car slid straight down with all four tires locked,” Gwyn Headley, a resident of Harlech, Wales, told Guinness World Records at the time. 

So residents of the town contacted the awards body to lodge an application. “Guinness World Records were very specific with the criteria and the qualifications that the surveyor would need to measure the street,” Headley said. “We had to get someone from Gwynedd Council who had the appropriate qualifications.”

The result: Ffordd Pen Llech, the Harlech street submitted as a contender for the record, came up with a gradient of 37.45 percent – handily beating Baldwin Street by over 2 percent.

It was a big win for the small town. “I cannot say how pleased we are that Ffordd Pen Llech has now been recognized as the steepest street,” Headley said, “not just in Wales, not just in the UK, not just in Europe, but in the entire world.”

But where did that leave Dunedin? Well, despite the popular photo poses, they didn’t take it lying down. “If Wales turns out to have a steeper [street],” Dunedin mayor Dave Cull reportedly said, “we will just have to arrange one of our periodic earthquakes and tilt Baldwin a bit more.”

Evidently, though, that was a bit difficult, so instead they opted to just appeal the decision. 

“The appeal, led by Toby Stoff, included a comparative survey of the three-dimensional shapes of the Dunedin street and Ffordd Pen Llech,” Guinness World Records explained less than a year later, in April 2020.

“The findings revealed that in order to fairly assess the different shape of the streets, whether they’re straight or curved, steepness must be measured by the central axis (the centre line of the road),” the company announced.

The new method of measurement changed the two gradients: Baldwin Street now measured 34.8 percent, while Fford Pen Llech was reduced to “just” 28.6 percent. New Zealand held the title once again.

But do they really deserve it?

A street steeper than the steepest street

Remember how Gwyn Headley talked about those very strict requirements for being awarded the record? Well, he wasn’t kidding: to qualify as even eligible for the title, a street has to be “a public thoroughfare that is commonly used by the public who have a right of access to drive vehicles along it to get from one destination to another.”

Sad news, then, for Hawaiʻi’s Waipiʻo Valley Road – with a gradient reported by data visualization scientist Stephen Von Worley in 2010 to reach a whopping 39 percent at points – which is currently ruled out for the world record. How can that work? Well, it’s actually so steep that, for safety reasons, access is restricted to all vehicles except four-wheel drives, and all visitors except residents. 

That’s officially a problem, as far as Guinness World Records is concerned: “the rules say the street must be completed and open to the public,” a spokesperson from the company told IFLScience, “but from what I can see the street is still closed to the public and can only be driven on by local residents.”

“But if anything changed in the future and it met the guidelines we’d be happy to review,” they added. There’s still a chance, Waipiʻo!

Still, even Waipiʻo isn’t the steepest in the world. In San Fransisco – famously a very hilly place indeed – there is one section of one road that has it beat.

“Carefully, I scaled the beast and measured it: a solid 30 feet of sustained 41% grade,” recalled Von Worsley in 2010. “On such a slope, gravity alone pulls a one-ton car downhill with 800 pounds of force, accelerating it from zero to sixty in 7.2 seconds. Whoa Nellie!”

“Congratulations, Bradford Street above Tompkins, for, having Bravely Thrust into the Forty-Percent-Plus Frontier,” he wrote. “You now stand alone atop the Peak Of Maximum Grades as the Most Tilted Paved Urban Thoroughfare In The World!”

A later post, in 2012, revealed that Bradford Street topped out even higher, at 42.8 percent – a gradient that would feel similar to climbing a flight of stairs. So why doesn’t San Fransisco take the Guinness World Record?

Well, it comes down to those pesky qualification criteria again. The Guinness record only requires that the gradient be maintained over 10 meters, since “if the average steepness is taken, you could have a road where one section is extremely steep and the rest is flat, which is not a fair assessment,” the company explains.

It’s really not a long distance – it’s just a little bit less than 10 meters (33 feet) – but it’s just enough to rule out that 9.1-meter (30-foot) section of Bradford Street. Sorry, San Fransisco: you’re out on a technicality.

Overall, then: congratulations, Dunedin, New Zealand – you still hold the Guinness World Record for the steepest street in the world. At least, until Wales figures out a way to rig the criteria back in their favor again.