Like one of these but on — and they’re not often let on in a Mercedes. Or turned on at all.

What should we do about those who never turn off their indicators on the highway?

We could try to pay them no mind but that’s easier said than done when you’re trying to plan when to indicate and merge yourself, as if perhaps they’re just signalling a mile out from the exit that they will be turning — as you’ve seen them do—but the truth is most likely that they don’t know that it’s on.