Turn signals are a small subset of the "signal knowledge and intent" lights/outputs that a self-driving car might want to use to communicate with the humans and

Turn signals are a small subset of the "signal knowledge and intent" lights/outputs that a self-driving car might want to use to communicate with the humans and, some day, other self-driving cars around. The team might be working in the direction of a more general implementation of such things rather than hooking up a temporary system for just two sets of dumb on-or-off lights.