The design of streets where people walk should begin with true 20 mph speed limits & Vision Zero principles by John Massengale Posted on August 12, 2015 #20isplenty #VisionZero About John Massengale Architect, Urbanist, Author, Educator View all posts by John Massengale → This entry was posted in Bicycle, Good Kind, Pedestrian, Slow Streets, Street Design, Urbanism. Bookmark the permalink.