As a new resident of Miami, my first reaction was a giant “no way.”
The local alternative weekly kindly points out that the methodology behind the ranking excludes weather and crime. So, yeah, Miami is a great place to walk around if you don’t mind getting rained on or mugged.
Another study lists Miami as the third most dangerous for pedestrians.
So, I have one thing to say to the greenies who’d have me walking around Miami to do my errands: you first.