Partly this is because there are 2-4 roads in parallel attempting to move the same number of people, or demand is unmet because people can't get to where they want to go when they want to go.
Honestly you're in the 11-15m range in most cases, because you want lineside equipment (signal cabinets, masts, cable routing etc) and ideally a 4WD path for maintenance access.
9m is doable but you don't built an entire system like that unless you really have to. Equally, your roads have hard shoulders and crash barriers.
Usually these systems rely on people getting on/off at different stops, rather than one stop seeing full volume. If it's one stop, chances are it'll look like a terminus station and you'll need several platforms and possibly dual-side boarding to each train. It'll be quite a bit wider than tracks with no station, or a minimalist station.
This is pretty common at major sports arenas.
The same of course applies to other transit options: high-capacity bus stops take up space, and motorway interchanges and especially carparks also take up a lot of space.
50k PPHPD is near the top of what can be easily achieved in a metro with one track per direction, but certainly achievable. 2x4m wide tracks and some space for ancillary equipment and fencing is reasonable.
You get maybe one passenger per two seconds in a car lane, or about 1800 per lane per hour. That implies 28 lanes each way, 55 total, or about 165m assuming 3m lanes (pretty narrow). Seems fair to me.
I'm assuming they moved to HFAs/HFCs for basically the same reasons refrigerants did: still non-toxic, still non-flammable, now no ozone concerns.
If they want to replace them with low-GHG alternatives it starts getting tricky.
Hydrocarbons are great but flammable, and flames inside your lungs seems even more exciting than some propane leaking out of your fridge.
Hydrofluoroolefins (1234yf and 1234ze) are probably about to be banned as PFOA precursors, although Wikipedia says the latter might be introduced in inhalers...
CO2 doesn't liquefy and breathing it in is going to make you feel like you're suffocating.
I'm picking HFCs are going to stick around in medical applications for a while where dust/liquid options aren't feasible.
That or returning to some kind of blower mechanism for ambient air.
Road design is part of it but improving road design only improves 'reasonable' drivers, and things like chicanes, lane narrowing, and speed bumps cause issues for larger commercial vehicles like buses.
Persistent asshole drivers will still drive drunk or drive dementia, run red lights, or go three times the speed a road is built for.
"the systems and environments we place people in" is not just the road. It's the licensing regime, the society that makes having a car necessary even if you can't drive safely or afford to maintain it, and that doesn't mandate effective ongoing training.
The point is that any unsigned image is assumed to be AI generated. You can absolutely strip the metadata or convert it to some other format (there's always the analog hole and it has to become a bitmap to be displayed) but then you've lost the proof you took it.
You'd still need secure key storage hardware and trust roots in the camera like TPMs but every phone has that already...
(This is referring to the 'signed in camera' model)
You also want a weapon you're familiar with and that you can control. In medieval farming communities, chances are everyone's used a pitchfork. Axe less so.
Pitchforks also work better as infantry; they're kind of a mini pike so they're useful in a mass and against horses. Swing an axe in a mob and it'll hit your neighbour.
Theoretically you could include the original signed unprocessed image (or make it available NFT-style) and let the viewer decide whether the difference to post-processed image is reasonable or unreasonable.
It would however make it impossible to partially censor images without giving away the non-AI proof, unless you had a trusted third party (TM) verify the original and re-sign the censored version.
A 'view cryptographically signed original' button next to every instagram post would be complete LOL, though.
Are you talking about the AI generator registering on the blockchain? Because there is essentially no incentive for them to do so and every incentive for them not to.
If you mean genuine camera images being registered on the blockchain, that would give away at minimum the time the image was taken, and probably what kind of device it was taken with and all other images taken by the same user. That's a lot of data.
Images, text etc can be generated entirely offline and independently. There is nothing to force the image to be attached to the block chain either directly or as a fingerprint.
You would have to do the opposite: when you take a picture or video (or write some text?), as it is recorded, the camera chipset signs the image/video using TPM-esque hardware, proving (ish) that it was captured by a real camera sensor.
The issue is that it's pretty close to mandatory doxxing.
You can but the track has to be built for it. Japan has stations that are passed at 320km/h (200mph). You need minimum four tracks (two platforms, two passing) and curves/gradients suitable for the speed, along with noise mitigations as necessary.
If you're trying to re-use tracks and stations built in the 1800s that's possibly less feasible.
Commercial planes often take off in mild tailwinds; they're typically certified for 10-15kt of tailwind. It's sometimes easier for the airport than re-sequencing all the flights especially if it's only a mild tailwind.
Florence has hills to one side (the west?) that mean taking off in that direction also carries a performance penalty because you need good engine-out climb rates. So it can be a choice of tailwind or hills.
It's all statistics. If you're never getting surprised by the weather, you are probably leaving money on the table. If it's happening all the time, you're selling too many seats.
It will also depend on how far out the last seat was sold.
Funny, $200 is standard in NZ if you pre pay. Can usually post pay though as you say.
Or guess how much fuel you're going to need and pre-auth a little more than that.