In this essay from GOOD, Alexandra Lange argues that planning cities with kids in mind has a better payoff for all age groups.
"Not planning for children in New York leads to all sorts of problems, small and great. For parents and caregivers, navigating the city can seem like a triathlon. You try holding fast to a three-year-old, carrying a shopping bag, folding a stroller to sling it over your shoulder, and not holding up the line to swipe your MetroCard on the bus-while six months pregnant. The most skilled at this maneuver do a graceful, quad-burning double or triple dip to pick everything up. But many turn to online shopping, and Fresh Direct, which isn't good for city tax revenues or the environment."