[pavon]

It's not clear what you mean by that. It is easy to build a city where you can reach everything you need within 15 minutes by car. What is hard is to build a city like that where you can also reach everything you need by foot within 15 minutes. I don't think it is as impossible as some urbanists make it though.

The downtown in my city is by far the most dense and walkable area of town while still being far more accommodating for car drivers than any of the areas that have been newly revitalized for walkability. The main difference is the existence of ample parking shelters where the main (st)roads hit downtown, unlike the new areas that insist on only having street parking to intentionally limit the number of cars. Both approaches allow the area to be designed for walkability first. But the former does a better job at accommodating people who don't live within 15-minutes by walking or public transit, and does a better job at keeping cars from being a nuisance. Because the motorists have a convenient place to park and walk they do so, while street parking only forces the cars into the walkable streets(and surrounding neighborhoods) to circle endlessly looking for a place to park and increasing congestion.

I really like the strong-towns framing of delineating roads vs streets which are designed for cars and pedestrians respectively. I think too many people are quick to jump on the assumption that roads==bad and streets==good, when having good roads and parking structures can relieve the pressure and allow your streets to be streets. At least in the short-term, and in the long-term you are going to want to keeps some sort of arterial land strips for public transit use (in all but the most dense areas which can support subways). So making them roads now with a mix of buses and cars that gradually becomes more buses, and then possibly dedicated public transit makes for a good growth plan.

[atoav]

Having some urban structure where everything is within 15 car minutes is easy. It is just not a metropolitan city. My (central european) 9000 inhabitant village/city was like that and there are many like it.

The issue is that this will not scale. The space needed for cars scales at a different rate than the space needed for people, so does the infrastructure.

Today I live for a decade in one of the biggest cities in Germany (a still quite car centric nation by European standards). I never owned a car in that city and never missed it. If I need one for the hardware store I can just get a car sharing one. I spent maybe 100 Euros on car and gas every year.

Most of what I need for my daily life is within walking radius (grocery store across the street, hairdresser, 24/7 drinks and cigarettes, some restaurants and bars on the street, the rehearsal space for my band is a 5 min walk where I don't have to cross a single road). It is quite silent in my area and the air is good (no dust/grime on the balcony).

If my area was car centric I'd have to sacrifice all of that. But what would I gain in return? The ability to go to all the places I can already go to by subway, S-Bahn, bus or bicycle? No thanks, I'd rather have my city human-sized than car-sized.

[JadeNB]

> It is easy to build a city where you can reach everything you need within 15 minutes by car.

I think getting to places by car is often not the hardest part. Instead, the hard part (at least from a user's perspective!) is storing all the cars for all the inhabitants of the city, both at their origin and their destination. This creates ballooning space requirements, including duplication of space (much residential parking will remain largely unused during the day, and much business parking will remain largely unused at night). Then, even after devoting as much space to cars as US cities do, one winds up unable to plan simply to drive to one's destination, but having also to devote significant planning to parking.

[kqr]

> It is easy to build a city where you can reach everything you need within 15 minutes by car.

Not when you account for congestion. Let's pretend that the average driver can accept sitting in traffic for one hour daily, or 30 minutes one way. What happens then is that more and more people will take the car until it's just congested enough to take 30 minutes to go somewhere -- even if the distance at full speed is just 15 minutes.

If you increase capacity more people will take the car until the trip takes 30 minutes again.

This just doesn't happen with less massive modes of transport because accommodating practically infinite amounts of foot traffic requires, comparatively speaking, very little area. Distances have to be shorter, yes, but scaling at a lower rate.