With some notable exceptions, current solarpunk seems to focus mainly on either cities or little cottagecore homesteads. But there are a lot of regions, especially in the United States, which don't look like either of these.

Exurbs, or bedroom communities, are rural/formerly-rural areas where people live but don't work. They're characterized by low density development (usually around 1-acre minimum building lots) and a lack of businesses or industry (often due to intentional zoning choices).

To quote an excellent write-up on the history of American suburbia and exurbia by Kate Wagner of Mcmansion Hell, “Exurbia is a low-density community built on previous farmland that requires a car trip to complete the most basic tasks, such as grocery shopping. It is a bedroom community - the working population commutes (by car) to work, and the young population goes to school.”

Exurbs are a direct product of the invention and popularization of the automobile. They're not viable without it. Their population is spread too thin and too widely to make effective use of public transit.

At least in the northeast US, communities were linked by trains within living memory. You used to be able to get on a train in several of the small towns I've lived in and ride it all the way to major cities. The tracks are still there. I grew up on stories from my grandparents of riding a horse and wagon (and later a Model A) into town and getting on the train, and they used the train to sell eggs and blocks of ice cut from the lakes (sometimes called the winter crop) to markets in Boston.

The catch is that the society was laid out a little differently. There were dense little towns linked by rail surrounded by much more scattered farms and forests. And even the farms tended to be a bit clumped up with their neighbors. The towns and villages, even those which were too small for rail, had a reason for being there. They set up in places with rivers for mills, things like that. People lived near their work.

People still had personal vehicles, especially the farmers and others who lived outside of town, but they generally only used them for local travel. Cars were remarkably unreliable and the idea of driving one across multiple states was

The modern day version of these rural areas is totally shaped by autoroads and cars. The community spread out into a sort of homogeneous mix of houses and forests, with many houses impractically far from work or anything else. Most rural towns where I've lived are 'bedroom communities' meaning they are mostly just a place people build houses with no business, basically suburbs with even less density. A lot of folks I knew drove for hours every day to get to work and a trip to reach a certain store would generally take at least an hour, some of that on highways.

So can that be changed? The construction of roads and houses in this pattern has a sort of ratcheting effect that locks a community in on cars. There's no other system that makes sense and allows for living in this format.

I think I'd argue that this format (enabled by a subsdized auto industry and subsidized cheap fuel) is itself impractical and can't be maintained indefinitely. Obviously that's a nonstarter for everyone who moved there so they could cut down the woods and live just out of sight of their neighbors, but I don't think it's something I actually have to convince them on. We've seen how fragile and complex the supply chains which provide vehicles, parts for maintenance , and fuel are. As far as pandemics went, COVID was a pretty gentle one and it caused shortages that made living out there more difficult despite the advantages of having your own space. I suspect the next few decades, maybe the next few years, will throw us more than enough supply chains problems to make living unnecessarily far from your work and your supplies difficult. I know a lot of folks living there with fantasies of being rugged survivalists when things get bad, but in the end of the day, they're commuters and shoppers, and all they routinely grow is grass.

If things go how I suspect they might, I think we'll see populations gradually start to centralize again. The important thing is to set up good, stable public transit like trains connecting the places where people gather. (And busses or even ropeways for small villages where terrain or population makes trains impractical). From there, smaller populations mean the roads probably get a bit worse, go an extra year or two before being repaved. And so on.

You'll still see plenty of personal vehicles out there, possibly more electric ones as it's easier to make your own electricity than it is to make your own gasoline or diesel. Woodgas conversion vehicles might also make sense for something you drive into town on special trips.

Travel might look like stoking up a woodgas pickup, riding over crumbling roads to the small town nearby, and getting on a bullet train to the nearby city. It wouldn't be much different from how my grandparents did things.

Edit: to go with this answer, I have a few more things worth considering:

Seasonal roads - plowing the roads in deeply rural areas is a practice a little newer than automobiles. At least in New England, snow rollers were a common answer to the issue of snow piling up on the roads. These giant, heavy rollers were pulled by horses and used to pack down the snow so sleighs could travel on it. People would either have two wagons, one with skis, or would convert their vehicles to match the season. There are mods for trucks and vans that swap wheels for skis in the front and tracks in the back. And ski groomers could function well in the roll of snow rollers, turning seasonal roads into effective winter trails.

Airships - these are a controversial vehicle but I think they make sense in the specific niche currently filled by large 18-wherler trucks. The trucks depend on a pretty high quality road network. If that network starts to crumble for lack of constant maintenance (and solarpunk advocates are generally pretty anti-car) then trucks may become less practical. They might deliver to villages which are off the train system, especially for bulk cargoes. Canada is apparently looking at them as an option as their northern ice roads become less reliable with the change in climate. https://canadiandefencereview.com/arctic-sovereignty-airships-for-the-arctic/

This aspect is pretty fun from a writing/worldbuilding standpoint. In the modern day, vehicle designs have taken on a degree of sameness, mostly due to safety requirements and the fact that each vehicle is trying to do every job at once. When every vehicle needs to be able to transport

If long-distance car commuting is no longer the default thanks to a return to public transit, and the condition of the roads effectively enforces a lower speed limit, then the vehicles which remain on the roads can be much more interesting. The modern default

As impacts and collision safety become less critical, and the ever-larger-vehicle arms race can taper off. Smaller vehicles, and more purpose-built vehicles (like bike based cargo contraptions) would have more room to operate if they weren't expected to travel at highway speeds and survive a headon collision there with a F350.

There'd have to be alternatives for by-default car commuting and long distance travel, as well as long-haul truck cargo (which generally needs better roads than regular passenger traffic). Ideally trains and other public transit could fill that niche, while cars and other personal vehicles would fill in the gaps. This is basically how the US operated prior to mass adoption of the automobile. I could even see cargo airships serving a similar role to cargo trucks for remote areas disconnected to trains and without suitable trucking roads.