Happened in Spokane WA, but I'm posting in General for the humor value.
https://www.king5.com/article/news/local/spokane-green-lights-turned-cannabis-leaves/293-47bb4f4e-938d-46c8-a133-99d0cf6c89d9
An individual identifying him/herself as the "Mad Signtist" installed cardboard cutouts on several Spokane traffic signals to make the green lights appear as cannabis leaves.