What I find to be a rather interesting tidbit related to this is that some applications (e.g. certain garbage collectors) map multiple ranges of virtual memory that address the same physical memory.
There are ways to avoid having buses stuck in traffic. Dedicated lanes for public transport, getting more people to use public transport rather than cars, and so on. So I'd say it's more often than not a choice in planning if it's convenient compared to using cars or not.
(There's also the problem of less developed systems often being less convenient, and because of it not having the funding needed to expand due to low usage)
Especially considering that OP posted a link to uniqkey a couple months ago on HN (not necessarily wrong, but considering that downloading the "whitepaper" also asks for a bunch of PI...)
At least Webhallen in Sweden sells them in physical stores around the country. Not sure about other places though.
Weirdly enough it's also cheaper to buy a 12m card there (500SEK instead of the usual 600SEK). Checked, and they're listed as a reseller on Mullvad's page so they must've gotten a good deal / are selling at a loss.