The UNISignal, which at this point seems to be only a concept, is currently designed to use a Triangle (Red), Circle (Amber/Yellow), and Square (Green) to add information to the signal for those of us with color deficiencies.
It seems like a pretty decent idea, and it could be especially helpful for those pesky horizontally-installed signals (I'm looking at you, Texas). However, I'm not sure about the symbols themselves. It seems that the triangle might be a better fit for the green indication (as it seems to be pointing up).
The official site, www.unisignal.com, is apparently only a placeholder. We'll have to wait to find out if the UNISignal has legs.
So what do you think? Is it time for shaped signal heads? Is it the answer? Is it solving a real problem, or just a perception?