As I understand, Comma.ai is focused on driver-assistance and not fully autonomous self-driving.
The features listed on the wikipedia are lane-centering, cruise-control, driver monitoring, and assisted lane change.[1]
The article I linked to from Starsky addresses how the first 90% is much easier than the last 10% and even cites "The S-Curve here is why Comma.ai, with 5–15 engineers, sees performance not wholly different than Tesla’s 100+ person autonomy team."
To give an example of the difficulty of the last 10%: I saw an engineer from Waymo give a talk about how they had a whole team dedicated to detecting emergency vehicle sirens and acting appropriately. Both false positives and false negatives could be catastrophic so they didn't have a lot of margin for error.