Tag Archives: modal split

Randal O’Toole has proposed a thought experiment that he uses to “debunk the smart growth myth” of the ideal walkable neighborhood grocery store.

“For smart growth to work, then population densities must be high enough for businesses to have enough customers within walking distance to keep them going. Smart growth won’t work if businesses in pedestrian-friendly neighborhoods must attract hordes of auto drivers from other areas in order to survive. A modern large supermarket needs to draw patrons from a community of about 40,000 people. This is known as the trade population for this kind of store.

Joel Garreau says that, as a rule of thumb, ‘the farthest distance an American will willingly walk before getting into a car’ is 600 feet. However, ‘if you do everything you can to make casual use of the automobile inconvenient at the same time that you make walking pleasant and attractive, you maybe, just maybe, can up the distance an American will willingly walk to 1,500 feet’…

The population density required to place 40,000 people within 1,500 feet of a grocery store is almost 124,000 people per square mile. That’s about two-and-one-half times the density of Manhattan.”

Therefore, smart growth won’t work. QED.

O’Toole has asked a worthwhile question but plugged in the wrong numbers to answer it. Out of curiosity, I’d like to take a closer look at this hypothetical scenario to see how feasible the walkable grocery may really be. Continue reading →