The Fair DUI flyer should work in California checkpoints. It will not work as well in most traffic stops because drivers are generally required to sign tickets in CA, which means you’d have to roll down your window.
We are working on an app that would allow drivers to take a picture of the ticket through a closed window and digitally sign it. Please sign up for our e-mail list if you’re interested in that app.
We strongly recommend that people discuss the Fair DUI flyer with a local lawyer before using it. Even if the lawyer doesn’t agree with us, you’ll be better prepared by having that conversation.