Walkable City is a book for mayors and planners of not-so-walkable places who want to rescue those places, not lose all their citizenry to San Francisco. The good news that the most effective measures are cheap and not too tricky. The bad news is that they're politically difficult. E.g., in many cases it's a good idea to eliminate free street parking; you want to charge enough such that consumers who drive in can find a parking space, park, shop quickly, and then be motivated to drive away from that parking space so that the next potential-customer can be assured of finding a space. Yay, more folks spending time in shops shopping instead of loitering. But small business owners keep thinking that charging for street parking will scare off customers… which makes intuitive sense, though it doesn't turn out that way in practice. But if you the mayor propose this and get a bunch of the small business owners mad at you, yeesh. So… good luck not being voted out as mayor before can save your city's downtown. Maybe you can hand this book to downtown merchants. Maybe it will convince them. Maybe?
Maybe not, though. I nod along with this book because I like dense-city life. But someone who doesn't feel that way might feel like the author's taking short cuts. Scientists who study this urban-planning stuff don't tend to measure "Will this change save your downtown?" because that's a tough thing to measure. What does that even mean? Instead they'll measure things like gasoline savings. Someone who already likes the idea of "walkable-ness" will nod along with the idea that gasoline-savings and less-time-in-traffic and happiness all correlate. But someone who doesn't think that way might wonder: How does this study measuring gasoline usage tell me that turning parking spaces into a bike-share station will help my local business?
Also, it's a survey, not going super-deep into anything. E.g., from this book I learned there's a point of diminishing returns for housing density. When folks say we should be concentrating less on adding housing to San Francisco's Mission District and more on the Saint Francis Wood neighborhood, it's not just because of some abstract notion like "fairness"; replacing a S.F.W. house with an apartment building + retail development eliminates more misery than doing so in the Mission, where the change wouldn't make much of a difference. Want to know the details? Hey, don't ask me; all I know is what I read in the book, not the underlying study. And this was news to me. And the book had maybe a paragraph about this. So… this pointed me at an idea that was new to me; but if I needed convincing, this probably wouldn't have been enough to convince me on its own.