Most Winding Road in Country

[roadman65]

https://www.dangerousroads.org/north-america/usa/4666-california-route-36.html

According to this article it does not say exactly that CA Route 36 is the most curvy route in America, but it does say that in 140 miles the road experiences many curves.  1811 it says to be exact.

Does anyone know of other roads that could contend for the title of most winding road in US?

[Rothman]

Tail of the Dragon and others in Appalachia come to mind.  I am sure KY and WV have some contenders.

[oscar]

Hawaii state route 360, and the Hana Highway part of county 31 to Kalepa Gulch south of Kipahulu. At least 600 hairpin curves, and a 15mph speed limit except in the immediate Hana area plus a 25mph "speed zone" in the Keanae area. Also dozens of one-lane bridges.

[hbelkins]

Tail of the Dragon and others in Appalachia come to mind.  I am sure KY and WV have some contenders.

US 129 gets a lot of hype, to the point that any other curvy mountainous route that's marketed as a good road for bikers and sports car drivers to try out gets a dragon-themed name. "Back of the Dragon" on VA 16 between Tazewell and Marion, "Dragon Slayer" on VA/KY 160 between Appalachia and Cumberland/Benham/Lynch, and a few routes that a Backroads of Appalachia group is promoting.

There's a four-digit state route, the number of which escapes my memory, that crosses Pine Mountain and connects KY 221 and US 119. It's nothing but curves.

[Max Rockatansky]

US 129/The Dragon is tame compared to what's out west.  US 191 on the Coronado Trail blows the doors off US 129/Dragon for sheer number of curves.  US 129 gets a lot of hype given it is easy accessible to the sports bike crowd and once had a much higher speed limit.  NC 28 IMO is the better drive/ride to go fast on from Deals Gap. 

Regarding Hana Highway I actually found it kind of chill all things considered.  The advertised about of curves Oscar stated is definitely a thing.  The one lane segments aren't too bad, they are well marked with yield signs.  The 15 MPH speed limit definitely isn't followed on the HI 360 segment, 25-35 MPH is more the average pace with faster traffic.  My thought coming away from Hana Highway was that it was like a more narrow CA 1 in the Big Sur area and more analogous to a Sign County Route.

CA 36 has a bunch of curves between US 101 and I-5.  That said, CA 36 wasn't exactly super haggard and probably has become less so since the one lane portion was expanded to two lanes.  CA 299 east of CA 96 to CA 3 in my opinion was the more curvy highway segment.  I want to say CA 245 has the most curves of any California State Route per mile.  Worth noting CA 36 is very tame east of I-5 with a lot of straight stretches.

With Oregon I would have to imagine the Historic Columbia River Highway would be the clear winner for curves per mile.  In Arizona the title likes to goes to AZ 88 for curves per miles.

That said, one that does stand out for me (not just with California) is Mineral King Road to southern extent of Sequoia National Park. 

https://www.gribblenation.org/2018/09/mineral-king-roadmountain-road-375.html?m=1

My intro description for Mineral King Road says it all:

"Mineral King Road is a 24.8 mile rural highway maintained by the National Park Service and as Tulare County Mountain Road 375.  Mineral King Road originates at California State Route 198 in Three Rivers near the confluence of the Middle Fork Kaweah River and the East Fork Kaweah River.  Mineral King Road climbs from a starting elevation of 1,400 feet above sea level to 7,830 feet above sea level at the White Chief Mine Trailhead in Mineral King Valley.  Notably Mineral King Road is stated to have 697 curves."

Some other notably curvy California roads that come to mind off the top of my head:

-  CA 155 east of CA 65.
-  CA 33 on the Maricopa Highway.
-  CA 2 Angeles Crest
-  CA 1 Cabrillo Highway in Big Sur
-  CA 1 Shoreline Highway
-  CA 58 west of Bakersfield
-  CA 198 west of Coalinga
-  CA 25
-  CA 9
-  CA 130
-  CA 180 east of Minkler
-  Generals Highway
-  CA 49 in the Merced River Canyon (the Mini Dragon as it is sometimes called)
-  CA 4 east of CA 207
-  US 199
-  Nacimiento-Ferguson Road
-  The Old Ridge Route (reportedly over 800 curves as originally configured)
-  Caliente-Bodfish Road
-  Kaiser Pass Road
-  Del Puerto Canyon Road
-  CA 23 in Decker Canyon
-  CA 74 (Palms to Pines Highway and Ortega Highway)
-  CA 243
-  CA 96
-  Eastern CA 169 (the one lane part)

[Rothman]

Tail of the Dragon and others in Appalachia come to mind.  I am sure KY and WV have some contenders.

US 129 gets a lot of hype, to the point that any other curvy mountainous route that's marketed as a good road for bikers and sports car drivers to try out gets a dragon-themed name. "Back of the Dragon" on VA 16 between Tazewell and Marion, "Dragon Slayer" on VA/KY 160 between Appalachia and Cumberland/Benham/Lynch, and a few routes that a Backroads of Appalachia group is promoting.

There's a four-digit state route, the number of which escapes my memory, that crosses Pine Mountain and connects KY 221 and US 119. It's nothing but curves.

Detour Road east of Paw Paw was also nothing but curves.  Glad I didn't meet a coal truck on it, too.

[MikieTimT]

One of my favorites is AR-16 between Clinton, AR and Fayetteville, AR.  You literally cannot get Google Maps to keep the route unless you add a couple of destinations/waypoints in the middle, like Deer and Boston, as there are faster routes both north and south a couple of counties.  It's got to be close to one of the curviest in curves/mile and crosses more than 1/3rd of the state.  Saw more deer and motorcycles than cars or trucks, and I can't recall a single semi on the route until near Fayetteville.  Did some timelapse videos of the route, and it's kind of nauseating.

[JayhawkCO]

For Colorado, I think I'd nominate CO141.

[Flint1979]

I've heard a lot of people say that M-119 is the curviest road in Michigan but I'm honestly not sure. M-119 is the Tunnel of Trees route in the NW lower peninsula.

[kurumi]

I wonder if there's a numeric value you could determine for this. Something involving:
* radius of curvature at centerline (smaller is better)
* number of curves (larger is better)
* length of road (normalizing factor for number of curves)

[Road Hog]

One of my favorites is AR-16 between Clinton, AR and Fayetteville, AR.  You literally cannot get Google Maps to keep the route unless you add a couple of destinations/waypoints in the middle, like Deer and Boston, as there are faster routes both north and south a couple of counties.  It's got to be close to one of the curviest in curves/mile and crosses more than 1/3rd of the state.  Saw more deer and motorcycles than cars or trucks, and I can't recall a single semi on the route until near Fayetteville.  Did some timelapse videos of the route, and it's kind of nauseating.

Once you get west of the pig trail, AR 16 is pretty much 55 the rest of the way. That's why it was a popular route before the advent of I-540/49.

[Scott5114]

I'll be the guy who mentions Lombard Street in SF.

[Max Rockatansky]

I'll be the guy who mentions Lombard Street in SF.

I'll be the guy who mentions Vermont Street has more curves.

[MikieTimT]

One of my favorites is AR-16 between Clinton, AR and Fayetteville, AR.  You literally cannot get Google Maps to keep the route unless you add a couple of destinations/waypoints in the middle, like Deer and Boston, as there are faster routes both north and south a couple of counties.  It's got to be close to one of the curviest in curves/mile and crosses more than 1/3rd of the state.  Saw more deer and motorcycles than cars or trucks, and I can't recall a single semi on the route until near Fayetteville.  Did some timelapse videos of the route, and it's kind of nauseating.

Once you get west of the pig trail, AR 16 is pretty much 55 the rest of the way. That's why it was a popular route before the advent of I-540/49.

Yeah, it straightens out between Brashears and Fayetteville for sure.  But the 133 miles between Brashears and Clinton are a biker's or sports car's dream.  There's virtually no one else outside of locals, hikers, or hunters that would go that far out into the wilderness otherwise.  There's literally only gas available in that stretch near the aforementioned ends, Deer, and Who DaThought It Arkansas.

[Bickendan]

I think OR 242 is probably the curviest per mile in Oregon.

[ozarkman417]

The Iron Mountain Road (US 16A) of South Dakota's Black Hills is worth mentioning. The seventeen mile stretch of road features 314 curves, including three loops where the road travels over itself. This equates to nearly 18 and a half curves per mile. Source

[Max Rockatansky]

So from what I'm reading in the thread so far the HI 360 portion of Hana Highway and Mineral King Road are leading so far with curves per mile:

HI 360/Hana Highway:  620 curves (source HDOT) in 34.4 miles for an average of 18.02 curves per mile. 
Tulare County Mountain Road 375/Mineral King Road:  597 curves in 24.8 miles for an average of 24.07 curves per mile.

Reportedly US 129 has 318 curves in the 11 mile Dragon segment (28.90 per mile).  Having driven US 129 over half a dozen times I tend to find that claim questionable, or at least I'm not sure what definition of a curve is being used.  Hana Highway and Mineral King definitely have more direction changed versus more length sweeping curves of The Dragon.   

[Flint1979]

I'll be the guy who mentions Lombard Street in SF.

That's probably the obvious winner lol. I was thinking of mentioning it earlier.

[Max Rockatansky]

I'll be the guy who mentions Lombard Street in SF.

That's probably the obvious winner lol. I was thinking of mentioning it earlier.

Problem is the rest of Lombard aside from the eastern part of Russian Hill is totally straight.  Vermont Street has more curves on it's big descent and is way shorter than Lombard.  Lombard isn't beating Vermont for number of curves or curves per mile in SF. 

[J N Winkler]

I wonder if there's a numeric value you could determine for this. Something involving:

* radius of curvature at centerline (smaller is better)

* number of curves (larger is better)

* length of road (normalizing factor for number of curves)

I'd certainly want to screen the various candidates by objective criteria.  The measure I personally favor is total degrees of change in bearing per unit length.  For example, if a road changes bearing 30° left and then 30° right in one mile but is otherwise straight, then that is 60° per mile.  To an extent this accounts for radius of curvature since curves of smaller radius waste less centerline length to change bearing over a given angle.  Curve count isn't helpful since it is possible for a single mile of an almost straight road to have thousands of short curves with microscopic bearing changes.

I think the windingest road I've personally driven is NM 159 between US 180 and Mogollon.  But while it is unquestionably in the 99th percentile, it is harder to defend the claim that it is number one in the country.  Essentially, if the road has an operating speed of 10 MPH or less and you never stop slewing the steering wheel back and forth, it is a contender.

[hbelkins]

If you look at a map, KY 30 east of Jackson in Breathitt County between KY 15 and the Magoffin County line looks to be very, very curvy. In reality, the map looks worse than the road really is when you drive it.

[Dirt Roads]

US-60 between Gauley Bridge and Ansted, West Virginia has 85 curves over in a little over 9 miles. 

It was wild back before I-64 was completed between Beckley and Sam Black Church, as there were several sections of truck climbing lanes on the steep grade heading east out of Gauley Bridge, many of which flipped around the hairpins.  The turns were two tight for many tractor-trailers (in both directions), so you had to carefully negotiate passing by anticipating that the big rigs needed to enter the center lane to lurch around the curve.  Sometimes you would slow down to allow the big rig you were wanting to pass upgrade to negotiate the next curve; sometimes you had to back way off because you just encountered a downhill big rig cutting off the curve from the other lane.  There was a few times that I "threaded the needle" between the two just to scare my unsuspecting passengers.

[Terry Shea]

I've heard a lot of people say that M-119 is the curviest road in Michigan but I'm honestly not sure. M-119 is the Tunnel of Trees route in the NW lower peninsula.

It's gotta be the entrance to Four Winds Casino (Four Winds Dr.) off from Wilson Rd.  This map doesn't really do it justice though.

https://www.google.com/maps/place/Four+Winds+Casino+New+Buffalo/@41.7813391,-86.7199641,15z/data=!4m5!3m4!1s0x88111b70eec75cc1:0x240b0c9c7e2db05f!8m2!3d41.7813352!4d-86.7089134

[Rothman]

If you look at a map, KY 30 east of Jackson in Breathitt County between KY 15 and the Magoffin County line looks to be very, very curvy. In reality, the map looks worse than the road really is when you drive it.

KY 122 across Abner Mountain is a curvy ride.  My grandfather used to call it their version of the Monte Carlo.

[citrus]

In the same vein as Vermont and Lombard Streets in SF....
there's also Cascadilla Park Road in Ithaca, NY. https://www.google.com/maps/@42.4434759,-76.4923156,18z