The Illustrated Technical Guide to the Accessibility Standard for the Design of Public Spaces published in 2014 by GAATES (Global Alliance on Accessible Technologies and Environments) is comprehensive. GAATES is based in Canada and refers to the Americans with Disabilities Act for standards, but they also include best practice features and design considerations. This means the design guide is applicable almost anywhere.
The guide is available as a Google Docs version or you can view it online. The Table of Contents lists: Paths of Travel, Recreational Trails, Beach Access Routes, Outdoor Public Use Eating Areas, Outdoor Play Spaces, Accessible Parking, Obtaining Service in Public Spaces, and Maintaining Accessible Public Spaces.