"Policy goals" won't be enough to protect bicyclists once the cars start driving themselves. Strong standards will be necessary to govern the interactions between cars and bikes in an autonomous future.
Poor neighborhoods tend to be fatter than rich ones, whether they are urban or suburban. However, poor urban areas tend to be thinner than poor suburban areas, and rich urban areas tend to be thinner than rich suburban areas.
Some media commentary suggests that fast-gentrifying cities such as Washington are unable to attract families. In Washington, the reality is more complex; the city's high-income neighborhoods actually gained children over the past decade.