I am hoping that we improve cities and towns so most people simply don't need to own a car. A cargo bike and the odd car-hire (like car2go) could replace car ownership for a lot of people, and make cities more pleasant.
To completely give up your car you'd have to put in place systems that allow you to function without it in all aspects of life. From suburban planning to doing your shopping. The amount of work needed is staggering. It took us a long time to see the damage of car culture, and it will take decades, if not longer, to change it.
I'm not actually saying that people shouldn't ever be able to drive, just that it should be reasonable for people to need cars rarely and be able to rent them for those occasions where they do.
But here in Berlin, I already have such a city: a 15 minute walk gives me a railway station, 22 stops for the metro and the bus, at least a dozen sit down restaurants and cafes, 17 supermarkets plus IDK how many corner shops, and both a construction store and a large home electronics store.
Try to do that today in Davis CA, and the closest you can manage is about half that and even then you're limited to one of Aggie Village, Old East, Old North, or on top of one of the shops or restaurants. Most of it has roads too wide to be a safe pedestrian option — I tried, I didn't feel safe, and it was relatively good compared to the other places I visited in the US!
How many people more can we fit in such Berlin?
However, "build millions of affordable houses really fast with almost no money" is something that this city, indeed the whole country and several adjacent countries, have done when they had to, so housing definitely isn't an insurmountable problem.
We're still regularly digging up the unexploded bombs from the same bombing runs that made rebuilding (with no money) necessary, but that's a local issue, you don't get so much of that in Washington or Mississippi. Or indeed (the original) Cambridge.
Wildly indeterminate on both questions because at that scale it is primarily a function of government rules and interventions rather than personal actions — just consider how much money people actually had when half the city was built.
But that also goes both ways, because a single building doesn't need to care about most of the infrastructure — sure, the site needs to have utility connections and a road, but you personally neither need to nor care to make the decisions about the capacity of the nearby sewage farm/high voltage power lines, or if there are enough schools/hospital beds/police stations, or if the Autobahn and Eisenbahn have enough capacity to supply the supermarkets.
I know it can be done cheap because of how little money there was when most of it was first put together, and that other much poorer nations also do many of these things.
But exactly how cheap? Exactly how green? I don't know if your investigation was professional or personal, but either way I suspect you have more to tell me than vice-versa.
The right question is, how do you copy what it does right at the lowest cost in the places that do it wrong?
Consider Vancouver Island for example, a number of small towns on the east coast of the island anchored by larger cities of Nanaimo and Victoria. They were connected together by a railroad.
As the age of cars took over the railroad tracks went into disrepair and were abandoned. We have a 19th century technology sitting right there to fix this problem. The only thing lacking is political will.
I've seen reports of cyclists who murder pedestrians through hit and runs. Sure this is rare, but we need to make sure the elderly are "safe" from belligerent cyclists and their poisonous online culture.
As such, it might be necessary for us all to walk, at least until we can develop practical systems to regulate speeds on bikes and ensure that the roads are not mad max style kill zone. I suggest a top bike speed limit of 10-12 km to ensure safe streets, with powerful automated brakes that prevent accidental pedestrian hits. It might flip the cyclist over xer handlebars but I'm sick of socializing risks and privatizing benefits; if you are in a rush, you should have left earlier.
Why settle for anything less than safety for decent society?
Incidentally, I agree with reducing polluting cars for pollution reduction measures. Sadly that means I don't care once we move to electric cars. You'll find most people are in that boat.
I'm amused that you think this is some sort of "gotcha". As someone who cycles, I would take this deal without hesitation it got rid of cars.
Of course, cycle-on-pedestrian deaths basically zero relative to the deaths caused by cars, so it's a worthless analogy. However, I do like the implication that we should be regulating transit based on momentum rather than just having special status for cars.
The MRI and everything was awful and I wish I had been able to do something to stop it. You are going to be disappointed if you think anything will keep our kids safe.
(Unrelated but in Japan, our health care did not cover the costs for the accident; the cyclist paid us for our out of pocket expenses as the police had found her pretty quickly)
Car crashes are a top 2 (often top 1) killer of children in ~every developed country. Cycling doesn't crack the top 10. Its intellectually dishonest to pretend that cars and bikes are comparable dangers to children.
As a sidenote, disregarding someone's life experience over statistics is antisocial behavior that only "works" on internet forums. You'll find, IRL, that RL stories are stickier and we need to listen and understand rather than just appeal to numbers (especially in post-truth "all numbers are lies" modern culture)
/rode a bicycle for more than 40 years, drove three kids on a Panasonic e-mama chari to baseball games and school. Way worse than a car.
There's a giant class of people that will be left behind if we get rid of cars, and they're being continually ignored by the anti-car movement. The pro bike / anti-car people have a point, but they will have to address this problem if they want to reach their end goals.
15% of the US is about 50,000,000 people. To reduce the fraction, that's 3 in 20 Americans. That's a lot of people to just hand-wave away and leave behind. These are people, not dinosaurs. They also control our food supply. I think it's in our best interest to account for them in our plan for the future, and treat them well.
I do question what my life would look like in that case - for the past 5 years I lived about 7 miles from work. I am currently in a college town while I am finishing up at university, and so I'm now: 3 miles from school, ~40 miles from work.
I use pseudo-public transport (a shuttle that my apartment complex provides / runs privately) to get to school every day. However, that situation works because there is a large group of people that need to go to exactly the same place (campus) at approximately the same time every day. I still need a car, because I often have to go to school late in the evening to use lab equipment when the shuttles don't run.
For work, it's even more important to have a car - a public transport route would likely take ~45 minutes compared to the ~12 minute drive on my old 7 mile commute. For the 40+ mile commute I have now, I'd likely have to jump between several different busses (go from my town to the town my company is at, then a bus from there to the regional airport where my office is). That would probably be at least an hour and a half, each way -- if you could even get the city to run a route from a hub to that regional airport.
All of this is not to mention trips I take just to explore, or to go hiking, or to see friends or family in distant towns, grocery shopping, or visiting a specific specialty store.
From what I've seen so far, the only people whose quality of life wouldn't be decimated by a lack of a car are the most privileged - young elites in major cities who live close to work (and can cycle there), who can afford the fees for an uber or taxi when they need one, or who work entirely remotely. The people in the lower and middle class who commute to work and want to go grab beers with friends a few miles away on their friday night - well, they're either forgotten, or mocked when they're remembered. It leaves a bad taste in the mouth for the whole thing.