The Street Plans Collaborative published the
Tactical Urbanist’s Guide to Materials and Design
it’s a guidebook on how urban residents can act to create streets and public spaces that are safe and accessible for everyone.
Good examples of tactical urbanism and organisations implementing these projects (e.g., San Francisco’s SFMTrA) are on our Act! page and Streets page.
See also: Your (Just a bit illegal) cheat sheet for hacking safer streets, by Aarian Marshall in Wired 16 December 2016.