Helpful Links
Here are some helpful web sites with resources which may answer questions you may have about detectable warnings or other ADA related issues:
U.S. Access Board
Federal Agency which oversees accessibility components of ADA.
ADAAG Standards
Americans with Disabilities Act Accessibility Guidelines. The Access Board (link above) issues standard minimum guidelines. This links to those guidelines.
ADA
Americans with Disabilities Act
FHWA
Federal Highway Administration
US Access Board
Detectable Warnings Update
US Access Board
Streets and Sidewalks
National Center on Accessibility
Indiana University site with topics regarding accessibility.
Accessible Design for the Blind Links
Additional website links