Related note: It'd be great if cities were more child friendly. A big challenge is cars, the 4000+ lb fast moving metal boxes... It'd be great if there were more car-minimal areas in cities, enclosed areas with parks and restaurants that had parking on the outside, but no cars and parking on the inside. And, in areas where there are cars, it'd be great if it went: sidewalk, bike lane, barrier, parking, then cars. That way there's a big "margin of safety" between where kids walk and where the cars are.