How would that work? On the highway, a slight nudge on a straight means you’ll cross a lane, meaning turn signals on.

A kilometer later, the exact same slight nudge could mean it’s just a light turn in the road, meaning signals off.

Now you could mandate cameras in all vehicles, which analyze your driving and turn on the turn signals when it thinks you’re making a turn. Now who’s responsible in a false positive if someone else dodges you and crashes because you suddenly turned on the signals without turning? Except it wasn’t you, but your car. Oh and also you made entry level cars 10k more expensive, making them way more inaccessible if you aren’t rich.