a new study in the American Journal of Epidemiology used 11,000 twins to show that whenever a neighborhood becomes 1 percent more walkable [...] residents walk 0.42 percent more minutes a week. So if a city boosts an area’s walkability by about 50 percent, an average resident might theoretically walk about 20 more minutes a week, according to the study.

I feel like there has to be a tipping point after which increases in walkability lead to much larger increases in minutes walked. It's not surprising that a 1% increase in walkability only leads to 0.42 percent more minutes of walking, because that's just a small tweak to an overall car-dominated hell. It seems like 50% more walkable would pass a threshold, making it safe and even enjoyable to walk.

In fact, there are plenty of anecdotes to that effect. It's great to see hard data like this; let's hope for more.

whenever a neighborhood becomes 1 percent more walkable

I can already see carbrains and NIMBYs argue against that 1% improvement, despite the massive benefits to individuals and communities.

Ideally, neighbourhoods should be 100% walkable when they are developed, and if there's no impact to safety or walkability, then the idea of introducing car traffic should be considered.

The way we work now, walkability is either an afterthought or simply not a consideration at all, and that hurts everyone.