I have such a system in my Corolla Cross, and I'd like to add that on top of all that - sometimes the system looses track of the lane and thus cannot follow it. Which is reasonable - it's only... nonhuman. What is not reasonable is that the only indication for that is a small indicator on the dashboard switching color from green to gray. That big-ass warning shouting at you? That's reserved for when you didn't play with the wheel for too long.