This Incredible Website Shows You Where The Good Driving Roads Are

It’s the long weekend and you have a fun car, a full tank of gas, and a good set of tires. It’s time to have fun, but where do you go? Of course, you can always wing it and see where the road takes you. Me personally? I want to make sure I get to get to my destination before dark, so if the goal is to find the best driving roads, and especially if I’m cut for time, I’m going to want to plan. Luckily, there is a website to help me find those twisties.

Curvature, whose tag line is “Find Twisty Roads,” is an open-source web application that uses data mapping to finding the curviest roads in the world, with the company saying:

Curvature helps those who enjoy twisty roads (such as motorcycle or driving enthusiasts) find promising roads that may not be well known. It works by looking at the geometry of every road segment and adding up how much length of the road is sharp corners, broad sweeping curves, and straight areas. The most twisty segments can then be viewed on the web or downloaded as KML map files that can be viewed in Google Earth.

To pull this off, Curvature relies on OpenStreetMap, commonly referred to as OSM. As the site suggests, it’s basically like contributing to a Wikipedia page; users can add details to the maps like road type, road surface, geographical markings, elevation changes, and traffic signs. This helps Curvature identify where the twistiest ones are.

When you open up Curvature, it looks like a bunch of psychedelic spaghetti. Refer to the legend though, and it all becomes quite clear. It’s yellow for least twisty, pink for the most, red in the middle.

The intention behind the program apparently comes from the heart. The founder, Adam Franco, a software developer, created Curvature as a passion project in 2012. As the company’s site notes, Franco built Curvature because he loves to lean into the turns:

Historically, our navigation tools like highway maps and GPS routing algorithms strive to help people get efficiently from one place to another, and in doing so place an emphasis on the “fastest route”, with the biggest roads and highest speeds. While these are often useful metrics, what they don’t capture easily and certainly don’t highlight is how fun a road might be to ride or drive. I wrote Curvature to builds maps that highlight how fun a road might be — where fun is defined as lots of time spent leaning into curves.

To demonstrate how it works, I’ll refer to his example of a route through the Adirondack mountains near where he lives in Connecticut:

As you can see, he uses Google Maps, which is full of bright details that are initially difficult to see. The lines that are visible to the naked eye in separate shades of yellow. The lighter the color, the less it is used as a main road. And then of course, the green and blue patches to indicate land changes and water channels.

Now let’s set a destination:

Okay, so it looks like Adam’s goal is reach Saranac Lake, NY some two hours away. Now the question is whether there are some great twisty roads for him to enjoy. To do that, we’ll pull up a Curvature map of the same area. This time with information fed from OSM into Curvature to see what comes up:

It looks like Adam is in for quite the adventure! At least three times on the route, he’ll encounter brief stretches where the road curves to a sizable degree, highlighted in red. Adam writes about the map we see above:

Pulling up the area in the area in the Curvature map, I can see that there a few smaller roads that are fabulously twisty and happen to generally parallel the most direct route. Curvature highlights the most twisty roads in a color-spectrum from yellow (moderately twisty) to pink (super twisty).

Note that the heavier, solid roads are ones that Curvature assumes are paved either because they have explicit surface tags entered in Open Street Map indicating they are paved, or are “primary” or “secondary” roads —which in most of the US and Europe are virtually always paved. The translucent roads are tertiary and smaller roads with no surface tags specified in Open Street Map yet.

You can see above that, when you click on a road, you get information about the surface, the length, and the curvature, with the latter being the important bit:

Now Let’s Try It For Ourselves

I live in Dallas-Fort Worth, TX near the airport. So even though I own a Miata, a 2021 MX-5 RF, finding time to break away is a challenge because I live in between the two cities — difficult but not impossible.

So I pull up the surrounding area, and voila:

Good news! There are a lot of colorful squiggles near me. A lot of them are orange to show decent curves if I feel like going for a leisure outing. But there’s one red line in the upper right corner that’s appealing. F.M. 455 that ends near McKinney, TX. The hilarious thing is I’ve actually been there and it is, indeed, a fun route to take. It’s been a while, I should go back.

Looking At David’s Hero Van Route

Soon, our very own David Tracy will fly out to St. Louis to rescue a $500 Toyota Sienna. Armed with tools and spare parts, he will attempt to coax life into it before setting off on a thousand-mile trek to Virginia before reaching his final destination in Chapel Hill, NC, where he will hand the keys to Jason to serve as his de-stressed hero van (all of his other cars are junk, and David fears this played into his recent heart troubles). Assuming David gets the van running, let’s explore what will come up on David’s journey.

As a quick reminder, here’s an outline of the route he plans to take:

Now, let’s pull up the Curvature results of the same area:

Okay, this bodes positive. I can tell he’s going to cross the Blue Ridge Mountains, but also some of the Appalachians and the surrounding Piedmont. Having lived in upstate New York previously, I know the east coast particularly well in terms of scenic beauty. That will be a pleasant drive to tackle.

You get the gist: All of us who write for this marvelous site keep a favorite driving destination in mind. For me, it’s north DFW country. For Matt Hardigee, it’s Blauvelt State Park hidden back upstate. For Thomas Hundal, it’s Rattlesnake Point where the old hillclimb course lies. We know how to have a great time.

Curvature isn’t perfect, with some rather flat roads appearing pink and some great roads seemingly not getting as much love as they deserve, but the idea behind the site is legitimately cool, and I implore our resident Wrencher of Rust Buckets to use Curvature and send pictures of the routes he takes along the way in that old van. God speed, David!

[Ed Note: Finding twisty roads will be the least of my concerns! It’s going to be like, one degree Fahrenheit in St. Louis, and I’ll be freezing my butt off trying to fix this van! -DT]

Image Credits: (Top graphic) Mazda; Stock.Adobe.com; (Story images) Curvature, author, David Tracy, Google Maps