An assignment by David Reinfurt, in his 2022 course in the Visual Arts Program at Princeton University, “Gestalt“:
Design an autonomous graphic form that means “Stop.”
More information at the dedicated website.
In Reinfurt’s 2019 book “A New Program for Graphic Design”, the “Stop” assignment is broadened by including also a “Go” sign.
As with the Stop sign, the Go sign must not rely on symbolic, graphic, or literal conventions. The Go sign will be directly related to, and dependent on, the form of the Stop sign.