[spacemanspiffii]

I would add to the top of that list - reducing the distance people travel. Less kilometers would be very effective. Don't spend hours a day in your car. If people wouldn't be traveling so much, especially for work, this whole problem would disappear.

[bluGill]

The whole point of a city is all the destinations you can teach. Less km means you can go less places. No density isn't an answer, because some destinations are not dense, and even if they are we can cram more places in.

[mcbobgorge]

Air travel is the best way to go long distances, but some small islands are not easily accessible by plane. For those places, we have ferries.

In a similar vein, most places in a city can be accessed via density + transit. But cars are great for those non-dense destinations you describe, like wilderness areas or farms or whatever else.

[bluGill]

There is a large gap between distances where flying makes S and and what you can walk. Even with an ebike the distance you can reach in a reasonable time is vastly less that a car for most trips.