Kauai Roads

[Max Rockatansky]

Looking for some suggestions on anything noteworthy road wise on Kauai that isn't State Highway or County Route.  I have a trip coming up the second week of November and current state highway inventory looks like a breeze:

https://hidot.hawaii.gov/highways/home/kauai/kauai-state-roads-and-highways/

Oscar's page doesn't really indicate anything interesting that wasn't a state or county route on Kauai:

http://www.hawaiihighways.com/kauai.htm

FWIW, I will have a Jeep on this trip since it was for some reason the cheapest option. 


Edit:  Saving stuff like this in clockwise order so I don't forget about them later:

6437 Opaekaa Rd (Truss Bridge)
https://maps.app.goo.gl/Fph75NSF4wj9evgN9

Spalding Monument and Hauaala Road
https://maps.app.goo.gl/Q8DKNpH5XZqKx99x6

AT&R - Moikeha Canal Bridge
https://maps.app.goo.gl/Pp4TBzSZ5XVo7DTP8

Old Rice Street Bridge off of HI 51:
https://maps.app.goo.gl/ZMisod564ZgHbc3GA

Old Hulemalu Road
https://maps.app.goo.gl/KckA5PDkVJcWgA1HA

Hanapepe Swinging Bridge
https://maps.app.goo.gl/dPBPAcGAvnWfktcc7

Older/Weird Hanapepe River Bridge (maybe former HI 50?)
https://maps.app.goo.gl/FyDCoiFF62frDH1L7

Menehune Ditch, Road and swing bridge over the Waimea River:
https://maps.app.goo.gl/tb1DoAhgtvkSER466

[formulanone]

Old Hulemalu Road was interesting, I don't know if it was formerly an SR nor not, since nothing was posted. Had a few nice views...







There's no road all the way around the island, but I suppose you need a 4WD/high-clearance vehicle to get to the northwest quadrant of the island, which is rather quiet. I wanted to check out Polihale SP, but chickened out in my rental car, and kind of ran out of time; that path seemed to peel off from SR 50's west end at the Pacific Missile Base.

I mostly stuck to the the state routes and posted county routes, although I did tackle a few dirt ATV roads.

[Max Rockatansky]

Polihale SP is my list as a "maybe."  It seems like that has to be a dry weather attempt and I'll have to check to see if it is off limits for rentals (the Big Island had a couple).

[formulanone]

I was pretty much wiped out physically after hiking Waimea; wanted to explore more bridges but would up just doing 550 to the top (watch for massive potholes!) and 552 on the way down.

The dirt part of Lawai Beach Road looks doable with a Jeep, would probably have a beach nearly to yourself there.

[oscar]

FWIW, I will have a Jeep on this trip since it was for some reason the cheapest option. 

I rented a Jeep last time I was there. It wasn't 4x4, and had the same crap OEM tires that I had on my 2006 Nissan Titan pickup (I replaced the tires after a slippery drive on an icy road in Arkansas).

You might check out a foot trail into the Alakai Swamp, which follows a proposed road to connect what is now HI 550 with HI 560. http://www.hawaiihighways.com/FAQs-page6.htm#Kauai-gap I've heard the trail might pass by remnants of the construction equipment stuck in the swamp after a futile attempt to build that road.

One nice thing I've heard about that swamp is that mosquitoes are not a problem. The swamp is at about 4000' altitude, too high for the mosquito breeds that infest Hawaii.

[Max Rockatansky]

This trip is underway, and I have my Day 1 photos edited:

https://flic.kr/s/aHBqjCzS8F

The album includes the following:

-  HI 570
-  HI 51
-  HI 58
-  Parts of HI 56
-  HI 583
-  HI 580
-  CR 581
-  HI 5600

Tomorrow is mostly stuff my wife and her friends want to see.  Most of it will be along HI 56 and HI 560 north/northwest from Kapaa.

[kurumi]

I found an interesting table in the 2014 Hawaii DOT transportation plan for Kauai: https://hidot.hawaii.gov/highways/files/2014/09/Regional-Federal-Aid-Highways-2035-Transportation-Plan-for-the-District-of-Kauai_Yong.pdf

Maps start page 88; highway log of sorts starts on page 93.

For example, Ala Kinoiki Way, which bypasses Koloa on the way to Poipu, and certainly looks like a state highway, is "secret" Route 522. I didn't see any 522 signage, even mileposts, when I was there 2 weeks ago (heck, even 520 is barely signed).

I'm guessing Lawai Road in Poipu (Route 523!) used to continue to Lawai, but there's a gate a short distance beyond Spouting Horn.

There's a fun abandoned sugar mill east of Koloa; you can't explore inside AFAICT but there's a lot to see from outside.

[oscar]

For example, Ala Kinoiki Way, which bypasses Koloa on the way to Poipu, and certainly looks like a state highway, is "secret" Route 522. I didn't see any 522 signage, even mileposts, when I was there 2 weeks ago (heck, even 520 is barely signed).

Neither Ala Kinoiki (route 522) nor route 520 is on Hawaii DOT's list of Kauai routes under state jurisdiction.

Kauai County's roads department is probably the best in Hawaii.

[Max Rockatansky]

The Day 2 photo album is up:

https://flic.kr/s/aHBqjCA1C8

Today was primarily focused on getting to Ha'ena State Park via HI 56 and HI 560.  Kuhio Highway was a priority item for pretty much everyone on this trip and that part of the day worked out nicely.  I don't think that I've seen such a large concentration of Bailey Bridges in one place as there is a bunch from the Wailua River northwards.

We had gotten back to Kapa'a around 4:40 PM.  My wife told me that she wanted to see sea turtles which had been coming up on the beach near the airport.  It turns out she was referring to Poipu Beach which for whatever reason was an estimated 85 minute drive from Kapa'a.  There was an approximately three mile long back up on HI 50 westbound departing Lihue which I can't really account for a cause on.  As far as I can tell it was just a backup caused by traffic departing Lihue on a Friday night and hitting a slow down when the west traffic lost a lane. 

The above did put me on Kauai County 520 and Ala Kinoiki Way.  Like Oscar said already there isn't any evidence of a Hawaii Route 522 or Kauai County of the same number.  I linked the current Kauai HIDOT inventory in the original post which doesn't describe such a route.

[Max Rockatansky]

I found Historic Roadway Plan for Kūhiō Highway (HI 560).  This was published in 2005 after the corridor was added to the NRHP:

https://hidot.hawaii.gov/highways/files/2025/02/Appendix-E-vol.-2.pdf

A related article with 1974 era information regarding replacement of the one lane bridges.

https://historichawaii.org/article/why-preserving-route-560-on-kauai-is-worth-fighting-for/

[Max Rockatansky]

The Day 3 album is up.  Today was Kauai County Routes 520 and 530 along with Hawaii Routes 540 and 541.  I also stopped in Hanapepe to see parts of the Old Kaumuali Highway.

https://www.flickr.com/gp/151828809@N08/3HN54v4pY8

[Max Rockatansky]

The Day 4 road photos are done:

https://www.flickr.com/gp/151828809@N08/d62Z4v6kPb

Today was Hawaii Routes 550 along with Kauai County Routes 543 and 552.  Surprisingly 552 was in far better shape than 550 was in the Waimea Canyon area.  I've found it rare for County Routes to be in far better condition when it comes to Hawaii. 

All and all this trip was fairly by the numbers.  I would agree with Oscar's assessment that Kauai County has the best and most consistent road department.  Pretty much every County Route is standard width with modern design features.  The only really odd item I thought was the super steep Bailey Bridge on Kauai County Route 581.

Also, the actual guide signage on Kauai is by far the best of the four Hawaiian islands I've been on.  Aside from 543 there isn't really any reassurance shields and directional placards that sneak up on you.  The assemblies reminded me a lot of Michigan. 

[Max Rockatansky]

Regarding something I noticed on Oscar's page regarding early Hawaii Route 583.  It appears the initial alignment served to permit access to the top of Hamamaula Ditch.  Said ditch was dug out in 1870 and has been repurposed as a tubing ride by Kauai Backcountry Adventures.  I thought something was a little odd when most of the road west of modern Hawaii Route 583 was eroded asphalt.

[Max Rockatansky]

Two additional finds today looking through the USGS maps.  What is now Hawaii Route 58 along Nawiliwili Road was originally numbered as Hawaii Route 501.  I suppose that makes sense given what is now Hawaii Route 580 was the original Hawaii Route 58.

Also, Hawaii Route 50 followed Rice Street from Lihue to Nawiliwili where it terminated at Hawaii Route 501.  This terminus is now where Hawaii Routes 51 and 58 now meet.  Both of these items can be seen on the 1963 USGS map of Lihue. 

[Max Rockatansky]

I found an interesting table in the 2014 Hawaii DOT transportation plan for Kauai: https://hidot.hawaii.gov/highways/files/2014/09/Regional-Federal-Aid-Highways-2035-Transportation-Plan-for-the-District-of-Kauai_Yong.pdf

Maps start page 88; highway log of sorts starts on page 93.

For example, Ala Kinoiki Way, which bypasses Koloa on the way to Poipu, and certainly looks like a state highway, is "secret" Route 522. I didn't see any 522 signage, even mileposts, when I was there 2 weeks ago (heck, even 520 is barely signed).

I'm guessing Lawai Road in Poipu (Route 523!) used to continue to Lawai, but there's a gate a short distance beyond Spouting Horn.

There's a fun abandoned sugar mill east of Koloa; you can't explore inside AFAICT but there's a lot to see from outside.

I stumbled upon this link when I was writing blogs up for the Big Island.  The state of Hawaii functionally seems to like to assign Federal Aid corridors with the same numbering sequence as they do for HIDOT road inventory and what the counties sign as County Routes.  I've never found a good way to reconcile this other than use what HIDOT has in their directory for roads they own along with what County Routes are signed in field.

Similarly, part of Kilauea Road to the Kilauea Lighthouse is assigned as Federal Aid route 562.  That particular Federal Aid corridor only applies to mileage 1.16 to 1.71.  Ala Kinoiki Way as Federal Aid route 522 by comparison comprised the entire corridor between mileage 0.00 to 3.32 since it was a brand-new roadway.

[formulanone]

Regarding something I noticed on Oscar's page regarding early Hawaii Route 583.  It appears the initial alignment served to permit access to the top of Hamamaula Ditch.  Said ditch was dug out in 1870 and has been repurposed as a tubing ride by Kauai Backcountry Adventures.  I thought something was a little odd when most of the road west of modern Hawaii Route 583 was eroded asphalt.

I took that tubing ride; the story went that the shovels wore out eventually and lots of people dug the canal ditches with their bare hands, or with spoons. Nice cool water for a hot June day, too.

I think they said the sugar plantations stopped around 1990 or so, it became less profitable to ship it all the way to California. Goodness, it's closer to Belle Glade, Florida at that point.

edit: grammar

[Max Rockatansky]

Regarding something I noticed on Oscar's page regarding early Hawaii Route 583.  It appears the initial alignment served to permit access to the top of Hamamaula Ditch.  Said ditch was dug out in 1870 and has been repurposed as a tubing ride by Kauai Backcountry Adventures.  I thought something was a little odd when most of the road west of modern Hawaii Route 583 was eroded asphalt.

I took that tubing ride; the story went that the shovels wore out eventually and lots of people dug the canal ditches with their bare hands, or spoons. Nice cool water for a hot June day, too.

I think they said the sugar plantations stopped around 1990 or so, it became less profit to shop it all the way to California. Goodness, it's closer to Belle Glade, Florida at that point.

I took the same tube ride.  I wasn't willing to risk my phone (dry bag or not) given I had lots of photos to offload (my wife took a lot those).  These vintage photos of the ditch caught my eye at the warehouse meet up point:

https://flic.kr/p/2rEjDqN

https://flic.kr/p/2rEjDpR

[oscar]

I stumbled upon this link when I was writing blogs up for the Big Island.  The state of Hawaii functionally seems to like to assign Federal Aid corridors with the same numbering sequence as they do for HIDOT road inventory and what the counties sign as County Routes.  I've never found a good way to reconcile this other than use what HIDOT has in their directory for roads they own along with what County Routes are signed in field.

Until 1968, the state and county routes were all in one network, with route numbers based on Federal-aid designations. Then the network was split into separate state and county networks, with the state keeping the best roads for itself. Some routes were renumbered in the process, but by and large pre-1968 FA numbers were preserved.

BTW, cutouts were phased out circa 1968. Sign thieves have stolen most of them.

[Max Rockatansky]

Apparently the Bailey Bridge at Keahua Stream opened in 2017.  This structure replaced the former ford which was present at the terminus of HI 580:

https://apnews.com/article/lifestyle-business-8f9e4ea9333249b0a496644f26b6bb64

And apparently it had a 75 year design lifespan:

https://acrow.com/wp-content/uploads/2025/05/Acrow-Case-Study-700XS-US-HI-Keahua-Arboretum-Kauai.pdf

$2.5 million isn't all that bad quite honestly:

https://dlnr.hawaii.gov/blog/2016/11/23/nr16-224/

[Max Rockatansky]

Apparently the 1920 era Wailua River Bridge had a deck replacement in 2009.  The replacement deck of course is a prefabricated Arcow truss.  It seems Kauai County went heavy on investing on Acrow spans due to their relatively low cost.  All the Bailey Bridges I referenced in previous replies seem to have been sourced from the company.

https://www.bridgehunter.com/bridge/70349

[Max Rockatansky]

I stumbled upon the NHRP registration report dated 9/5/2000.  This is mainly focused on the 10 miles of Kuhio Highway comprising HI 560 but includes a lot of history on the larger Kauai Belt Road:

https://npgallery.nps.gov/NRHP/GetAsset/NRHP/03001048_text

Of particular note the Kauai County Supervisor proposed a $100,000 bond in 1915 to construct the Mana-Haena segment of the Kauai Belt Road (now Kooke Road).  The bond didn't pass but the intent was to fun completion of the Belt Road by 1917-1918.

[Max Rockatansky]

Found this document on the Library of Congress page regarding the history of the 1938 Hanapepe River Bridge (HI 50).  It goes into quite a bit of detail about the 1911 span (which still exists) and Hanapepe in general.  The 1938 structure was recently replaced in 2019.

https://tile.loc.gov/storage-services/master/pnp/habshaer/hi/hi1000/hi1048/data/hi1048data.pdf

https://www.loc.gov/item/hi1048/

Some general highways of the recent widening of HI 50 in the Puhi-Lihue area:

https://hidot.hawaii.gov/highways/first-segment-of-kaumualii-highway-widening-project-complete-next-phase-begins/

A 1903 Hawaii Territory survey map of Kauai.  This map has some interesting features such as the early Hanalei Hill alignment prior to the Hanalei Grade being constructed in 1911:

https://www.loc.gov/resource/g4382k.ct002423/?r=0.161,0.334,0.202,0.098,0

[Max Rockatansky]

I did some work on Kauai County Routes 520 and 530 today on my page.  Two items of note came up:

-  The Koloa Tree Tunnel (520) was planted in 1911.  The 500 eucalyptus trees were donated by Walter McBryde.
-  Hawaii Routes 52 and 53 originally had a mutual terminus at Poipu Road in Koloa.  This arrangement was carried over initially when 52 was spun off into the Kauai County system.  Kauai County Route 520 first shows extended to vicinity of Koloa Landing at the intersection of Poipu Road/Lawai Road on the 1983 USGS map.

[Max Rockatansky]

Apparently, the Koloa Bypass opened around August 2001.  The project was delayed from opening in March due to the original contractor applying too thing of a surface.  Ala Kinoiki Way was selected as the road name during October 2020.  The Federal Aid Highway 522 designation is interesting in that it seems Kauai County intends to extend the Koloa Bypass west to Kauai County Route 530 (Koloa Road).  Really at that point this corridor should (IMO) get a Kauai Route designation:

https://archives.starbulletin.com/2001/06/10/news/story2.html

https://www.thegardenisland.com/2001/06/23/news/mayor-koloa-bypass-could-be-open-by-august/

https://www.thegardenisland.com/2000/09/26/hawaii-news/contest-on-to-name-koloa-bypass-road/

[Max Rockatansky]

Started my initial work on Hawaii Route 540.  I found an item of interest on the 1956 Gousha map of Hawaii.  It appears very early Hawaii Route 54 was aligned through the McBryde Sugar Company town of Numila via Sugar Mill Road and McBryde New Mill Road. 

https://www.davidrumsey.com/luna/servlet/detail/RUMSEY~8~1~212233~5500303:Oahu--Kauai--Maui--Molokai--Hawaii-?sort=Pub_List_No_InitialSort%2CPub_Date%2CPub_List_No%2CSeries_No&mi=4&trs=5&qvq=q:hawaii%20highway;sort:Pub_List_No_InitialSort%2CPub_Date%2CPub_List_No%2CSeries_No;lc:RUMSEY~8~1

The modern bypass of Numila used by Hawaii Route 540 first appears on the 1963 USGS map of Hanapepe. 

When I was on Kauai my wife wanted to see the Kauai Coffee Estate which is located just west of Numila.  I didn't see any signage on McBryde New Mill Road saying it was off limits, so I had look for myself.  I suspected an older alignment, and it appears I was correct.

IMG_7504 by Max Rockatansky, on Flickr