A 10 AM Bay Area earthquake is the highest plausibility * severity event you're likely to experience around here on a day to day basis - leaving some people with a 25 mile commute back to a structure that might or might not be standing, intermittent at best communications, and potentially impassible roads.
IMO if you don't have a case of water, a road map, and a change of walking-around clothes in your car around here, you're asking for smiting. Fortunately that's about $10 in total, and you can drink the water even if there's not an earthquake.
Additionally, near everything that would be handy in case of an earthquake (gloves, pry bar, basic trauma supplies, etc) is useful in case of a car crash, which actually is far more likely.
The great part about preparedness planning is there is a kind of vaccination herd immunity effect at play. The more people who take minimal measures like you list, the less intensive efforts preparedness-minded have to invest into. To your example, if 90%+ drivers keep a flat of bottled water, then it makes sense to only keep a water filter at one's home instead of one in the car for long trips and one at home.
However, Just In Time doesn't just permeate our supply chains, but many people's personal lives. So the lists of what it takes to ride out life's inevitable curve balls grow ever longer.
That's one of the ideas of Community Emergency Response Teams (CERT / NERT).
During the 1989 Loma Prieta earthquake, citizens banded together and helped each other other because emergency services were overwhelmed. Afterwards, they reached out to the fire department to ask for formal training and thus NERT (Neighborhood Emergency Response Team) was born.
When the next big earthquake hits California, we still won't be ready. However if neighbors pitch in and can put out small fires and shut off gas leaks before they turn into anything more serious, then that's one less neighborhood the fire department has on their to-do list.
I highly recommend anyone in earthquake country to take a NERT/CERT class to help out their neighborhood.
Your comment got me thinking about some form of volunteer force of medics. Imagine if every 20th car that drove by had a government issued medical bag in the trunk and a driver guaranteed to have recent first aid and emergency training. And in return the driver gets some sort of tax break, or an HOV lane free pass, or whatever the appropriate incentive is. Surely some country has tried this out.
In Israel about one tenth of the population has undergone combat training, and I suppose about one twentyith of those are combat medics (including myself). We get no tax breaks or other incentives, but when the once-in-ten-years emergency pops up, we are quite appreciated.
From talking to other medics, I see that most of us carry simple useful tools, such as a cloth triangle, everywhere we go. And we're well-versed in improvising.
In many European countries, you won't get a driver's licence unless you pass a first aid test. And I think in some places it may also be required to have certain emergency equipment in your car.
The laws protecting the helper definitely help as well. As long as I'm not tremendously reckless or meanspirited I cannot be blamed (sued) for any damage I do in the course of providing first response aid. In fact I can be sued for not trying (calling for help is sufficient).
The US has so-called "Good Samaritan" laws as well. Some of them go so far as to protect untrained individuals who injure or kill someone while attempting to render aid.
That depends on your state. I took one for my first license but haven't had a driving test since when I've moved between states. I have had paper and oral exams since then, though. But that only shows I know the laws and rules of traffic, not the ability to drive.
Most first-world countries are not obsessed with self-elevation and interest resulting from their own infrastructure breaking down
Third-world countries might be more the incubator you're hoping for but they generally don't care what happens to the non wealthy (and the wealthy's FO plans there as with everywhere don't involve looting cars on interstates)
So if I were to guess, I'd go with no, no "other countries have tried this out".
E.g. in much of Europe you're not getting a driving licence without passing a first aid+CPR course, and every car must have a first aid kit and a fire extinguisher.
Also, I recall that USSR had mandatory civil defence courses in universities - so everyone with a college degree, no matter if it's medicine or math, will have had a full semester of disaster followup & related issues; didn't USA have something similar during the cold war?
There are search and rescue volunteers, and most counties have a team (that's usually roughly proportional in size to the population of the county), and while they don't get tax breaks, a few places are nice enough to offer them discounts here and there.
Medical training varies from team to team, but a minimum of wilderness first aid is pretty typical. EMT is pretty popular too.
The water in most municipal systems is chlorinated in some way, and kept under pressure while in the system. Once the water is no longer under pressure, the chlorination compound can be degraded by UV light (sunlight), heat, gaseous diffusion, and time, to the point where it is no longer in the correct form and concentration to be effective against biological contaminants.
So it isn't as though it "goes bad" like food does, but the safety factor against unsafe handling goes away.
The other problem is that materials from an unsuitable storage container could slowly leach into the water, like plasticizers or metals. If you store water in mason jars and seal them as though it were food to be preserved, that water will not "go bad" until the lid rusts through, and depending on the possible contaminants, you can probably still drink it after bringing it back up to a boil.
As for myself, I keep much of my water stockpile frozen in plastic 2L bottles, because it keeps the freezer temperature more stable under normal circumstances, and keeps the rest of the stuff in the freezer frozen longer in case of power outages. You can always pull one out and drop it into a cooler for short outings, to keep the drinks and egg salad cold. And then, after it melts, you can still drink it. The only tradeoff is that it takes up space in there.
IMO tsunami in the bay area would be equally plausible with a much higher potential severity. When a tsunami hits a bay, the waves will rise. Further, with Alameda and Oakland at just a few feet above sea level... well...
I want to leave water in my car, but it gets so hot in there I'm afraid of what is leached into the water from the plastic. I've read a lot of conflicting information about this.
As others have said, you're not gonna be drinking it every day...
Stuff like BPA is not acutely toxic. There are some concerns about long-term ("subchronic") exposures spanning a decade or more, and even there, there is basically no clear evidence of adverse effects on humans.
Besides, BPA and its ilk are a concern chiefly with a variety of fancier, transparent plastics. Food-grade HDPE and polypropylene jugs are of relatively little concern. They are just not particularly pretty, so they don't sell.
Steel and glass are two other options, although many steel bottles are lined with epoxy or other coatings. Plus, in a car accident, I'd rather have a soft HDPE jug flying around...
I wouldn't worry about this for an "emergency" supply - especially for a small supply like you'd be able to keep in your car. If you break down on a hot day away from town somewhere, I'm sure you'll be glad to have a gallon of water with you, BPAs be damned.
Having left some water in a car in hot climate for some time (probably more than one but less than three weeks), I don't need studies to tell me that I don't want to drink it. My tastebuds do a sufficiently good job.
It's both heavy and fragile. I don't trust plastic to drink out of habitually, but there's virtually no risk to expected from short term use of food-grade plastic and it's much more practical in difficult situations.
Plastic also has the advantage that you can use it to sterilize water. Glass blocks too much UV, but a couple of days in the sun will disinfect water in a clear plastic container. You can have safe water indefinitely just by rotating containers (at least here in the Pacific Northwet, where availability of some kind of fresh water is more or less assured).
IMO if you don't have a case of water, a road map, and a change of walking-around clothes in your car around here, you're asking for smiting. Fortunately that's about $10 in total, and you can drink the water even if there's not an earthquake.
Additionally, near everything that would be handy in case of an earthquake (gloves, pry bar, basic trauma supplies, etc) is useful in case of a car crash, which actually is far more likely.