One of the biggest problems with this idea of producing lots of food in urban areas in that urban land is very expensive and transportation will only become more efficient over time. So why are we obsessing on reducing transportation distance? Trains are incredibly efficient and trucks will only improve, especially with increased automation.<p>Transportation costs will fall, but urban land values will continue to increase. Just look at the housing situation in the San Francisco metro area. It&#x27;s more efficient to use urban areas for people and grow crops where they grow well.