[NeedMoreTea]

Depends what you visualise as urban, I'd expect that small and medium towns surrounded by agricultural and horticultural production that serve the town, and large enough to have public transport links are most efficient. Conurbations and mega cities can't be anything like as efficient or sustainable.

[bryanlarsen]

- small towns don't use container ships, which are far more efficient than anything else

- small towns tend to have longer trips from the grocery store to your house, which is where most transportation costs occur

[NeedMoreTea]

> small towns don't use container ships

Nor do most major cities. The vast bulk of UK and most country's trade goes through just their top 6 or 8 ports. The container comes off a ship, then gets to the other cities and towns via rail or road. You get a similar picture across most regions.

> small towns tend to have longer trips from the grocery store

Not in my experience. Usually far less travel, and less congestion to the shops and superstore. There may be fewer stores overall. I'm assuming the town is large enough to have at least one supermarket here. You may well be right if you're thinking of having to make a trip to the next town over to do the shopping.