Hawaii - Update on which rental car companies allow saddle road driving?

I'm starting to think about renting a car for a trip to the Big Island in August.

In 2006 we were careful to rent from a company that allows driving on the saddle road, and we took advantage of that to park at the 9000-ft visitor center at Mauna Kea and then hike up to the top.

I'd like to be able to do this again, but I can't remember which rental car company we used, and things may have changed since 2006 anyway.

So, does anybody knpw for sure which companies are currently allowing driving on the saddle road?

Thanks for any advice.

I'm starting to think about renting a car for a trip to the Big Island in August.

In 2006 we were careful to rent from a company that allows driving on the saddle road, and we took advantage of that to park at the 9000-ft visitor center at Mauna Kea and then hike up to the top.

I'd like to be able to do this again, but I can't remember which rental car company we used, and things may have changed since 2006 anyway.

So, does anybody knpw for sure which companies are currently allowing driving on the saddle road?

Thanks for any advice.


OK, I will start checking out KOA-based agencies one by one to answer my own question and I will post results in the hope this will be of use to others.

First out of the gate: a friendly Alamo rep called the KOA office and verified that saddle road driving is OK with Alamo.

I can concur with the above. I've always used Alamo in Hawaii. Besides giving me the cheapest rates, they do allow to drive on certain roads (like Saddle) that isn't allowed on other companies.

personally Saddle Road gets a bad rap imho, it should be taken off the no-drive list some of these companies have. It's way more improved and quite nice to drive. Unlike State Highway 31 (near Kaupo) on Maui. Now that road is hell to drive on and yet Alamo allows me to drive on that one as well.

TS out

The reason there was ever a ban on Saddle Road for rental cars was the expense of retrieving one if it were to break down up there. A flatbed truck is required and they charge a lot to drive up there & come back down.

The road is getting a straightening / re-route and is progressing nicely, but it may still be the case that some rental companies will be averse to allowing their cars up there.

Best to check in advance.

I do believe Harper Rentals (local company) allows vehicles anywhere on the BI. And they rent 4WD for those who wish to drive all the way to the summit of Mauna Loa.

4WD is required for the dirt sections from Visitors center (9000ft) to the summit (13,500ft) so you can have low range going down hill and not boil your brake fluid.

I'm going out on a limb here but I 'think' you'll find that none of the major rental companies will prohibit you from using the saddle road. Hey, it's paved & it's in the USA! :)

That road has never even been mentioned in my rental contracts.

Wow, I'm having a 'yikes!' moment here. My daughter used to live Hilo-side, so when I visited, we always used her car everywhere. Since she moved (to Buffalo!), now I have to rent when I go back. It never ever occurred to me that the rental company might have a problem with me driving Saddle Road. I knew about going up to Mauna Kea (saw a stranded rental jeep when we went up there), but not Saddle Road. Guess I better check next time.

None of the major rental car companies currently prohibit driving Saddle Rd - although you might want to double check Thrift and Dollar. Someone left their Thrifty contract in the lav on my flight back and I noticed it had so many disclaimers about this and that, I know never to rent from them.

If you drive Saddle Rd, the middle part is re-aligned and paved - but - the western side is still the old-fashioned two-lane, hilly, road which is subject to diverse drivers and blinding fog. The eastern side near Hilo is under construction, and subject to delays during the week.

Although not explicitly stated, all rental car companies bar driving the Mauna Kea access road to the summit because a portion is unpaved.

I drove the Saddle Road, plus up to the Visitor's Center last year and I can't imagine any rental car company having a problem with it. The eastern half is practically a 4-line highway and the west side isn't much different than an average rural country road. I didn't even give it a second thought. I've heard stories of how bad it used to be, but it's a non-story nowadays, IMHO.

I rented from DTG (I forget which counter I went to, but same difference) on 16 February and the only prohibitions were Waipio Valley, the Green Sand Beach road at South Point, and the summit of Mauna Kea. Saddle Road and Mauna Kea Access Road up to the visitor station/end of the pavement are apparently fine.

I can remember the days - not so long ago - when rental agencies told me all of Saddle Road was off-limits, but with the improvements and realignment proceeding apace, the part of the road on the actual "saddle" is in great shape now, very modern, safe and easy to drive, and the slopes at the ends are getting fixed, so even though it's still terribly inconvenient to get a tow truck up there, people are less likely to get into trouble and need one.

I rented from DTG (I forget which counter I went to, but same difference) on 16 February and the only prohibitions were Waipio Valley, the Green Sand Beach road at South Point, and the summit of Mauna Kea. Saddle Road and Mauna Kea Access Road up to the visitor station/end of the pavement are apparently fine.

I can remember the days - not so long ago - when rental agencies told me all of Saddle Road was off-limits, but with the improvements and realignment proceeding apace, the part of the road on the actual "saddle" is in great shape now, very modern, safe and easy to drive, and the slopes at the ends are getting fixed, so even though it's still terribly inconvenient to get a tow truck up there, people are less likely to get into trouble and need one.

Agreed. Its amazing the transformation that the saddle road has gone through... and is continuing to go thru. The KOA side is much improved, [although it was kinda fun before] and the ITO side is an epic change...

Here's a pic from Jan of a bit of the construction heading towards ITO

http://farm6.static.flickr.com/5006/5359732256_ca2eb3fffa_z.jpg (http://www.flickr.com/photos/beckoa/5359732256/)

Got my Alamo contract and they allow Saddle Road driving and driving up to the Mauna Kea observatory. They however, do not allow driving up to the summit as the road is not paved.

We didn't plan to go to the summit anyways because we have an infant 1 year old, and many have recommended not to go up to the summit with small children. So the contract is a bit of a moot point anyways.

Got my Alamo contract and they allow Saddle Road driving and driving up to the Mauna Kea observatory. They however, do not allow driving up to the summit as the road is not paved.

Tiny correction: the Mauna Kea Observatories are on the summit. :)

The contract allows driving up to the end of the paved road at about 9,300 feet. That's far enough for astronomers to get to the "Hale Pohaku" complex just before the end of the paved road, where observatory night staff sleep during the day - they'd take an observatory-owned 4WD the rest of the way.

Just below that complex - maybe 1/4 mile before the end of the paved road - is the Visitor Information Station (VIS), which has the gift shop, snacks, hot cocoa, movies, stargazing, and so on and so forth. Both of those are part of the "Ellison Onizuka Center for International Astronomy" (named after the Hawaii-born astronaut who died in the 1986 Challenger explosion).

(I was going to lead a summit tour from the VIS this Saturday, March 5, but it was cancelled due to a winter storm.)

I do believe Harper Rentals (local company) allows vehicles anywhere on the BI. And they rent 4WD for those who wish to drive all the way to the summit of Mauna Loa.

Do you happen to have a ballpark figure on how much it is to rent the cheapest 4WD for a day?

Do you happen to have a ballpark figure on how much it is to rent the cheapest 4WD for a day?

You don't need to pay the Harper's premium for a 4wd - just rent one for a day from the airport (if you're staying south) or National at the Hilton Waikoloa Village.

Do you happen to have a ballpark figure on how much it is to rent the cheapest 4WD for a day?

You don't need one. If you are renting a somewhat decent car you will be fine with it. I been to the summit in a Ford Fusion in 2009 and Saturn Vue in 2008. You don't need an SUV to drive to the top. It's a simple dirt road pretty much any car will get to the top. When coming back down shift the transmission into second gear (both automatic and manual cars can do this). Even if you don't shift down and just use the breaks on the way down you will still be fine. There is no point spending extra money on getting an SUV just to get to the summit.

You don't need one. If you are renting a somewhat decent car you will be fine with it. I been to the summit in a Ford Fusion in 2009 and Saturn Vue in 2008. You don't need an SUV to drive to the top. It's a simple dirt road pretty much any car will get to the top. When coming back down shift the transmission into second gear (both automatic and manual cars can do this). Even if you don't shift down and just use the breaks on the way down you will still be fine. There is no point spending extra money on getting an SUV just to get to the summit.

I have to strongly disagree - this can be very dangerous advise for someone who has never driven to the summit before. People have died on the way down due to their brakes overheating.

A regular car is fine if driving to the visitor center, but a 4WD with 4-LO gear is essential for safely driving to/from the summit. When I was up a couple months ago, I saw a couple in an older sedan try and drive up after picking up two foreign tourists at the visitor center - they were having a very tough time getting up the inclines and had to pull over frequently which created a hazard for everyone else. I didn't witness their trip down.

I have to strongly disagree - this can be very dangerous advise for someone who has never driven to the summit before. People have died on the way down due to their brakes overheating.

A regular car is fine if driving to the visitor center, but a 4WD with 4-LO gear is essential for safely driving to/from the summit. When I was up a couple months ago, I saw a couple in an older sedan try and drive up after picking up two foreign tourists at the visitor center - they were having a very tough time getting up the inclines and had to pull over frequently which created a hazard for everyone else. I didn't witness their trip down.

When going up their is less and less air which causes the car to loose power. If the car for example was underpowered and/or too heavy I do agree with you that they likely didn't make it all and were a hazard for everyone else. Going down though their really shouldn't be a problem if you put the transition in a low gear. Last time I went their we had some friends who's daughter wasn't feeling well (was sick) so they rushed back down to the visitor center. They only used their breaks and they were fine as well.
This is the road for anyone interested: http://maps.google.ca/maps?hl=en&q=big+island&ie=UTF8&sll=19.762892,-155.452761&sspn=0.002762,0.003449&rq=1&ev=zo&split=1&radius=0.13&hq=big+island&hnear=&ll=19.762927,-155.452624&spn=0,0.003363&t=h&z=18&layer=c&cbll=19.762927,-155.452624&panoid=-FoWiH33kH1Hdgk7AhSfXg&cbp=12,84.9,,0,15.36

When going up their is less and less air which causes the car to loose power. If the car for example was underpowered and/or too heavy I do agree with you that they likely didn't make it all and were a hazard for everyone else. Going down though their really shouldn't be a problem if you put the transition in a low gear. Last time I went their we had some friends who's daughter wasn't feeling well (was sick) so they rushed back down to the visitor center. They only used their breaks and they were fine as well.
This is the road for anyone interested: http://maps.google.ca/maps?hl=en&q=big+island&ie=UTF8&sll=19.762892,-155.452761&sspn=0.002762,0.003449&rq=1&ev=zo&split=1&radius=0.13&hq=big+island&hnear=&ll=19.762927,-155.452624&spn=0,0.003363&t=h&z=18&layer=c&cbll=19.762927,-155.452624&panoid=-FoWiH33kH1Hdgk7AhSfXg&cbp=12,84.9,,0,15.36

The lower air density is exactly what makes the road so dangerous on the descent - less air to cool the brakes results in quick overheating. On most cars, 2nd gear is not low enough to control speed and 1st is too low and can result in engine or transmission overheat or failure.

Just because some people have made it up to and down from the summit without incident doesn't make it a sound practice. I've been to Mauna Kea many times and we have at least one forum member who works there - there is no way I would recommend or endorse the use of a regular car (especially one you don't own) on the summit access road.

There is nothing wrong with reserving a 4WD at the Hilton, parking your regular rental in their lot (which is free until they fix the gate), taking their 4WD up, then returning it after the evening tour. You can leave the keys with the Hilton valet, grab the regular rental car and drive back to the hotel/condo from there - even easier to do if one is staying at/near the Hilton. With a little planning and a National code from our very own National forum, this can be done quite inexpensively and at a fraction of the cost of Harper's.

Thanks.

I actually did the drive up to the summit about 6 years ago, and I couldn't remember how much we paid for a 4x4 Jeep but it was much less than $200/day (the current quote on Alamo).

I also remember seeing all kinds of cars at the top - sedans, compacts, etc. I think I even saw a Buick LeSabre which was quite funny at the time. But... I'm really not a rule breaker when it comes to these kinds of things. Are they still strict about having a 4x4 past a certain altitude?

Thanks.

I actually did the drive up to the summit about 6 years ago, and I couldn't remember how much we paid for a 4x4 Jeep but it was much less than $200/day (the current quote on Alamo).

I also remember seeing all kinds of cars at the top - sedans, compacts, etc. I think I even saw a Buick LeSabre which was quite funny at the time. But... I'm really not a rule breaker when it comes to these kinds of things. Are they still strict about having a 4x4 past a certain altitude?

If the warden catches you driving up they *might* stop you and turn you around, although I've never seen that happen, and like you, I've seen plenty of inappropriate cars on the summit - *can* you drive a regular sedan to the summit? Yes. *Should* you drive a regular sedan to the summit? No.

You don't need one. If you are renting a somewhat decent car you will be fine with it. I been to the summit in a Ford Fusion in 2009 and Saturn Vue in 2008. You don't need an SUV to drive to the top. It's a simple dirt road pretty much any car will get to the top. When coming back down shift the transmission into second gear (both automatic and manual cars can do this). Even if you don't shift down and just use the breaks on the way down you will still be fine. There is no point spending extra money on getting an SUV just to get to the summit.

Worst advice ever.

I have personally seen cars and 4wd vehicles that had crashed coming down the Mauna Kea summit road. I have seen vehicles in the visitor center parking lot with smoke pouring out of the wheel wells due to over using the brakes.

I have been to the summit 100+ times over the past 12 years. Always in a 4wd pickup. On the un-paved section, I use 4-low range and 2nd gear. This allows me to use both my brakes and my transmission to control the downhill speed. On the paved sections I use 2nd or 1st in 2wd, and use my brakes as necessary.

What happens if you just use brakes downhill at altitude?

The friction of the brakes creates lots of heat.
The heat is conducted to the brake system lines, caliper parts, and wheel cylinders.

This heat, combined with the low atmospheric pressure at high altitude, causes the brake fluid to boil off. *Liquids boil at lower temperatures at high altitudes. Refer to the baking instructions of a cake mix in your pantry. You will see separate instructions for folks who live at higher altitudes.

So now your brake lines contain a gas instead of a liquid. This results in soft, mushy brakes, and if you continue to do this, you will lose the stopping power of the brakes completely.

Its the density of liquid brake fluid that allows sufficient pressure to squeeze the brake calipers, and push out the wheel cylinders. When you replace part/all of this liquid with a gas, you cannot reach sufficient pressures to grip the brake discs/drums.

Nuff said.

As others have pointed out, using your brakes too much on the way down from the summit (because, say, you don't have a 4WD transaxle that gives you a low range of gears, and therefore can't engine-brake sufficiently, OR you don't know how to properly use brakes in this situation - brake hard for a few seconds to cut a lot of speed, then let them cool for a bit, instead of braking gently all the time) will make them heat up and stop being useful.

And yes, that can kill you (http://the.honoluluadvertiser.com/article/2007/Apr/20/br/br6419508237.html) or destroy your shiny brand-new vehicle (http://darkerview.com/darkview/index.php?/archives/1820-Accident-on-Mauna-Kea-Access-Road.html).

If you're going up Mauna Kea in anything that doesn't have real 4WD with low-range - and that includes anything AWD - I'd suggest that do yourself (and the local First Responders) a huge favor, and make plenty of stops on the way down to sightsee while your brakes cool off. For example:


Take pictures by the "Mauna Kea Ice Age Natural Reserve" sign just below the summit
Stop at the paved parking lot on your left just below the pass. Check out the view, or walk across to the gravel helipad and hike the trail to Lake Waiau.
Take the dirt road on your left out to see the VLBA radio dish and take pictures there.
Stop at the paved parking lot near the bottom of the upper pavement, or the little dirt pull-off even closer to the bottom of the pavement, to check out the big valley below.
A bit below mile marker 4 on the dirt, there's a corner to the left. Pull off around there and take in the view.
Between mile markers 2 and 3 on the dirt, there's a hairpin to the right with an obvious dirt parking area on the left. Pull off there and check out the fenced Mauna Kea Silversword plant.
Between mile markers 1 and 2 on the dirt, there's a hairpin to the left with a pulloff on the right. Might be another Ice Age Natural Reserve sign, and there's a little trail that goes out to the main summit trail, or you could just check out the view some more.
Obviously, stop at the Visitor Station. See if your brakes smell funny. See if they're glowing an interesting color (red? yellow? blue?). Check out things there, shop, get a drink, use the bathroom, whatever.
Below the Visitor Station, there are places along the 17% downhill grade where you can pull off and look at the western side of the Saddle. There's also space to pull over near the runaway truck ramp further down. And there's a little stub driveway on the right just after you pass the plastic-lined retention basin on the left. Feral sheep, wild turkeys and Hawaiian Nene geese are sometimes seen in this area.

Obviously, stop at the Visitor Station. See if your brakes smell funny. See if they're glowing an interesting color (red? yellow? blue?). Check out things there, shop, get a drink, use the bathroom, whatever.[/LIST]

And at the Visitor Center, they sell brake fluid! That should be a hint.

Please, don't take unqualified vehicles to the summit. And that includes many small SUV's (like the Hyundai Santa Fe with the small 4 cylinder engine) that don't have enough cubic inches and compression to significantly retard your downward progress without over-revving, thus taxing your brakes.

So, officially, if I get a powerful enough 4WD from the major agency (and not Harpers), isn't there still a clause in the rental contract that forbids you to drive up to Mauna Kea summit? Or is that clause limited to the 2WD?

We are going there in Easter. Doing the tour seems so expensive ($200 pp), Harper's 4WD is rather expensive. So, wondering whether we can hire a National 4WD and go to the summit ourselves?

Thanks

Ken

So, officially, if I get a powerful enough 4WD from the major agency (and not Harpers), isn't there still a clause in the rental contract that forbids you to drive up to Mauna Kea summit? Or is that clause limited to the 2WD?

Probably, yes. I'm not sure whether any of the major rental chains have relaxed those prohibitions yet. And they usually seem to state the prohibition after you book (but before you pay), so it's kind of hard to find out.


We are going there in Easter. Doing the tour seems so expensive ($200 pp), Harper's 4WD is rather expensive. So, wondering whether we can hire a National 4WD and go to the summit ourselves?

People violate that clause in their rental agreements all the time - I see it happen. The obvious risk is if anything goes wrong and you have to call the rental company for help from somewhere you're not supposed to be... ;)

(Yeah, I've seen that happen, too!)

Probably, yes. I'm not sure whether any of the major rental chains have relaxed those prohibitions yet. And they usually seem to state the prohibition after you book (but before you pay), so it's kind of hard to find out.



People violate that clause in their rental agreements all the time - I see it happen. The obvious risk is if anything goes wrong and you have to call the rental company for help from somewhere you're not supposed to be... ;)

(Yeah, I've seen that happen, too!)

Thanks, I guess we will take our chances.

Thanks, I guess we will take our chances.

Definitely the visitor center is accessible by all rentals.. just to the summit its unpaved..

If you want to go up the Summit Safely, there are free ranger tours up to the summit three times a week I think..

http://www.ifa.hawaii.edu/info/vis/

If you want to go up the Summit Safely, there are free ranger tours up to the summit three times a week I think.

http://www.ifa.hawaii.edu/info/vis/

The "escorted" tours from the Visitor Information Station are only on weekends (Sat/Sun) and the ranger is along for safety, not leading the tour. You still need to bring your own 4WD, and you'll drive up in a line of cars. You're on your own coming back down. ;) That tour typically goes into the visitor gallery of the Keck I telescope - one of the largest 2 on the mountain. The exact link with all the info is:

http://www.ifa.hawaii.edu/info/vis/visiting-mauna-kea/summit-tours.html

Japan's national Subaru Telescope - the third largest up there - also offers official tours on most Tuesdays, Wednesdays and Thursdays. You still need to bring your own 4WD, and you meet the tour guide at the observatory on the summit. You get to see much more of the inside of Subaru on this tour than you will see of Keck on the VIS tour. There are three groups a day - one in Japanese, one in English, and another in Japanese - and they're limited to 8 people each. And since it's an official observatory tour, yes, there are liability waiver forms! You can reserve spots on the Subaru Telescope's web site, at:

http://www.naoj.org/Information/Tour/Summit/index.html

If you've only been on one of these two tours, I'd definitely recommend the other. And if you haven't been on either, well, take both. ;)

/intimately acquainted with both of these tours

The "escorted" tours from the Visitor Information Station are only on weekends (Sat/Sun) and the ranger is along for safety, not leading the tour. You still need to bring your own 4WD, and you'll drive up in a line of cars. You're on your own coming back down. ;) That tour typically goes into the visitor gallery of the Keck I telescope - one of the largest 2 on the mountain. The exact link with all the info is:

http://www.ifa.hawaii.edu/info/vis/visiting-mauna-kea/summit-tours.html

Japan's national Subaru Telescope - the third largest up there - also offers official tours on most Tuesdays, Wednesdays and Thursdays. You still need to bring your own 4WD, and you meet the tour guide at the observatory on the summit. You get to see much more of the inside of Subaru on this tour than you will see of Keck on the VIS tour. There are three groups a day - one in Japanese, one in English, and another in Japanese - and they're limited to 8 people each. And since it's an official observatory tour, yes, there are liability waiver forms! You can reserve spots on the Subaru Telescope's web site, at:

http://www.naoj.org/Information/Tour/Summit/index.html

If you've only been on one of these two tours, I'd definitely recommend the other. And if you haven't been on either, well, take both. ;)

/intimately acquainted with both of these tours

Great information DanTravels..

We've only been up to the visitor center, and haven't tried the tours up to the summit yet.. since we have a 6 year old and 1 year old, and I don't they are recommended to go up until 12 years old, maybe its been recently changed to 18 years of age..

What do you think about bringing your own 4WD to the summit.. Where would you rent.. and do these rangers care if the rental agreement allows trekking up to the summit or not?

What do you think about bringing your own 4WD to the summit.. Where would you rent.. and do these rangers care if the rental agreement allows trekking up to the summit or not?

I actually have an old compact SUV, which has 4WD but lacks the low-range gearing that is really great for getting back down the mountain safely. That's the main reason they want people in 4WDs - higher odds of getting back down! I've only driven it up to about 12,000 feet so far, but the girl I bought it from took it to the summit a few times.

I have rented from Harper's once or twice in the past. I reserved once from somewhere else (Alamo?) but after reserving was shown terms saying I couldn't take the 4WD to the summit (or anywhere else off-road!) so I canceled it and went with Harper's.

That said, the Rangers, VIS staff, VIS volunteers and observatory staff do not care at all where you got your 4WD, or what terms and conditions you agreed to, or whether you are violating those terms and conditions. A rental agreement is between you and the rental company and doesn't involve any of us mountain folk. ;)

We've only been up to the visitor center, and haven't tried the tours up to the summit yet.. since we have a 6 year old and 1 year old, and I don't they are recommended to go up until 12 years old, maybe its been recently changed to 18 years of age..

I've only known the requirements since 2004 when I first went on the VIS guided tour, but at least since then, the requirement has been 16 years old, for the VIS tour, the Subaru tour, and as far as I know, the commercial sunset and sunrise tours and any private tours of other observatories.

That said, everybody handles altitude differently.

I've seen healthy adults pass out up there at a wide range of ages. I went on the VIS summit tour a few weeks ago with a thirty-something friend from Japan, and she dropped at the end of the tour. The Ranger said another tourist a couple buildings away had gone down at the same time. Just last week I was on a tour of Subaru with a professor or two and some students, and a twenty-something girl went down - although a lengthy explanation of some very technical topic by one of the professors may have had something to do with that. ;)

On the flip side, when my daughter was 6 I told her that if she wanted to see the summit before she was 16, she'd have to hike there with me - figuring that hiking would give more time to adapt to altitude and hiking up is much, much harder than just walking around on flat ground up there. So she started practicing hiking on the mountain every summer during school break, and now has pictures of herself all hale and hearty at the Keck Observatory at the ripe old age of 12.

So the moral of the story is, conditioning and preparation are at least as much factors as age. Oh, and now's a great time to start your 6-year-old hiking on mountains. :D

That said, everybody handles altitude differently.


That sure is the truth. I'm in good shape, but I had trouble climbing a flight of steps at the summit. I learned that there is a big difference between Haleakala at 10,000 feet and Mauna Kea at over 13,000.

That sure is the truth. I'm in good shape, but I had trouble climbing a flight of steps at the summit. I learned that there is a big difference between Haleakala at 10,000 feet and Mauna Kea at over 13,000.

Very important to note - acclimation is vital. Going from the shores of Waikoloa to the summit of Mauna Kea in one 2 hour stretch is going to leave a person laying on the ground or barfing for sure.

I am far from being in great shape, but spending 90 minutes at the Visitors Center for dinner and some strolling around prepped me adequately for the summit and I was not only able to walk around, but made the hike up to Pu'u Weiku with a spring in my step and had energy for more...while on the stepped trail up, I passed a couple of rather "fit" folks who looked like they were on death's doorstep.

So....acclimate acclimate acclimate...and you'll have a much better time up there.

I'm in good shape, but I had trouble climbing a flight of steps at the summit. I learned that there is a big difference between Haleakala at 10,000 feet and Mauna Kea at over 13,000.

Oh my, yes. The parking lot at the top of Haleakala has a little flight of stairs up to a scenic viewpoint, with a sign saying not to run. On Mauna Kea, there are no such signs... probably because if running up stairs there even crosses your mind, you have serious mental issues. :D

Very important to note - acclimation is vital. Going from the shores of Waikoloa to the summit of Mauna Kea in one 2 hour stretch is going to leave a person laying on the ground or barfing for sure.

If they stay up there long enough, probably. The minimum 30-minute acclimatization at the VIS is enough for a quick drive around the summit, but if you're going to be standing, walking, hiking, and so on... the more, the better. Consider that in most cases the actual astronomers - who go there more often than most of us - stay at the dorms just up the road there for a full 24 hours before going up for a night.

Oh my, yes. The parking lot at the top of Haleakala has a little flight of stairs up to a scenic viewpoint, with a sign saying not to run. On Mauna Kea, there are no such signs... probably because if running up stairs there even crosses your mind, you have serious mental issues. :D

I've ridden up to that lookout on Haleakala many times on a road bike -- no problem. Walking up a flight of steps after driving to the top of Mauna Kea -- problem.