I flagged the driver down, not to remonstrate, but to warn her (it was a her, with a polite Southern accent) of the danger from other cars that might not be expecting any oncoming traffic as they trustingly hurtled into the Old Post Road from the intersection just ahead of her.
She thanked me. And then asked me for directions.*
*To get where she wanted to go, I told her it was quicker and easier for her to keep going the wrong way for the remaining fifty yards or so. Was that wrong?