Just took a look at "The Urbanist Case for a New Community in Solano County"... and they got nothing

[This project appears to have stalled, but don't worry, there are plenty of other plans for badly placed, car-dependent exurbs waiting in the wings.]

Don't get me wrong. This document has lots of ideas, some impractical, some with a horrible real-life track record, some silly, and yes, some genuinely good, but when it comes to the primary obstacles to achieving the various high sounding goals, it has nothing. At least nothing with a snowball's chance in hell of working.

I may take a deeper dive one of these days, but for now let's focus on the exurb problem (there are others but that's the big one). The proposed city is perfectly situated for car dependence, lacking any rail service and far enough from major population and employment centers (San Francisco, Oakland, Sacramento, Stockton) to rule out any form of transportation other than automobiles, but close enough that almost everyone will be willing to make the drive.

The fundamental contradiction of a green exurb is never really addressed, but the way the author skirts the issues suggests that it's on their mind; they just don't want to talk about it.

We realize that the California Forever proposal is a big change in the thinking of many urbanists, who equate ”greenfield” with ”sprawl” - low-density, auto-oriented development. We know, most greenfield development is sprawl, even when developers use words like walkable. But there are exceptions. Seaside, FL was a greenfield development, but it’s not sprawl [Remind me to talk about Seaside, Florida as an example of planned urban development. We'll have a lot of fun with that one. – – MP] . And the plan we have put forward is not ”sprawl” either - it’s medium-density, high-quality urbanism. And again, the plan even has a legally binding minimum density standard to make sure we hold ourselves accountable to our walkability goals. We are literally prohibiting ourselves from building sprawl.

We are dealing with a narrow and rather interesting definition sprawl here, and one that doesn't apply to some fairly notable examples. When we talk about a city like Alpharetta being a case of urban sprawl, we are referring to the distance between it and Atlanta. The fact that Alpharetta's downtown is fairly dense isn't all that relevant. Whenever someone use the word walkable, it begs the question walk to where? If the vast majority of jobs, shops, universities, restaurants, bars and entertainment venues are accessible only by car, the fact that you can stroll down to the neighborhood Coffee Bean doesn't actually mean a hell of a lot.

Another place where the author almost hits on the issue of car dependency is in the section on parking. [Emphasis in the original.]

A smart parking strategy. Parking minimums for new buildings in this community are set at zero. While homeowners can build parking garages if they wish, we will provide shared community parking garages - some located at the edge of the community, some located at carefully selected locations throughout the city. We have given careful thought to the design of the garages, with seamless transfers to public transit at each location. We will also operate a robust car-sharing program, providing access to a car without the hassle and expense of having to own one. All of this translates into some important objectives for us: reduced cost of construction so we can deliver homes more people can afford; reduced cost of transportation for households; reduced urban footprint devoted to storing cars. We understand that people are going to need to drive sometimes, as they do in the rest of the region. The mode split for external trips will probably mirror infill development in the Bay Area. [Remember, unlike the Bay Area, this development has no rail whatsoever. -- MP] But the California Forever city plan will encourage less car use for internal trips, with all the benefits this creates for people’s health, social connections, and the environment.

If you want to keep your bearings during this discussion, here's the one fact you have to keep your eye on: while you may (and the "may" is doing a great deal of work there) have lots of appealing options for internal trips, most of those will be under 5 miles. You basically have one option external trips and most of those will be more than 50 miles, and as mentioned before, the vast majority of jobs, stores, restaurants, colleges, museums, nightclubs, and entertainment venues will require external trips, at least for years to come.

The virtues of car sharing have been greatly overhyped, but you can at least make a case for the approach in major urban areas. In an exurb, it is completely unworkable. It's difficult to imagine bus lines running frequently and for long enough hours for people to get by on them solely. Rail service would require entirely new track to be laid and is, at a bare minimum, more than a decade away. Even if things go exactly as planned (and there are any number of reasons to think that they won't) it is difficult to imagine a substantial number of people choosing to live in a place like this without a car.

There are rules-based approaches that might reduce car ownership and force people to make use of other options. You could limit households to only one car. You could ban private garages. You could move all public garages to the outskirts of town. You could greatly increase parking fees. You could make not having a car at all a condition for subsidized housing. I'm not saying any of those would be good ideas, but they represent the kind of thing you would need to do to get people to go without cars in this situation. Unfortunately, there is a strong recurring libertarian thread running through these proposals. If you give people living in an exurb the freedom to choose their mode of transportation, you're not going to like their choices.