Some big Australian cities work reasonably well with 'cars optional' suburb. They have an overall feel and lifestyle that I imagine would be familiar and comfortable enough for most American suburb dwellers.
For a quick and dirty snapshot: Suburbs are considered similar to small 'urban towns.' They typically have a train station (some Sydney suburbs have cool ferry stations) at the centres and the suburb stretches for a 1-2 mile radius from there. They are usually denser and have a more town center feel near the center. Inner city suburbs feel more urban. The really distant suburbs are more car centric and often have a semi-rural feel. Suburbs on the Dandenong foothills in Melbourne are a cool example of this.
Basically the nearer the city centre and suburb centre you live, the less cars are necessary or convenient. It's not extreme though. Most people have cars everywhere but the level of use varies. I would estimate that >50% live someplace where car free living is possible without too many trade offs.
Realistically though, the way to prevent cars is to make them unaffordable. That's an option, but I don't think you can call it a victory for quality of life by itself if it's achieved by making something people want unaffordable.
You are talking about something that has very little to do with the population density and zoning of an American midwestern suburb: What we mean is something like this, where having no car makes you a second class citizen.
What you call a suburb is more like what in Spain are called 'ciudades dormitorio': Small towns with a much higher population density than the american suburb, and that have good communications with downtown. People live less than a mile away from a train station that drops them in a public transportation hub in downtown Madrid. It's still a suburb, but it has absolutely nothing to do with what an American describes.
What s sustainable and economical public transport? And what is that population density? Are US suburbs less dense than European ones? Or is there less Will to publicly finance public transport? Funding road construction with tax money but not having a public transport system on those roads with 50-100% tax funding is just asking for congestion, sprawl and pollution.
I live in a smallish suburb with mostly single family houses 30 minutes by bus from the city. Buses leave every 10 minutes, and every 2-3 minutes during commute hours. I would never commute by car, especially since the buses use bus lanes.
