It happened while I was reviewing a European automaker’s flagship luxury sedan.

I was creeping along on Interstate 93 in Boston, testing the active cruise-control system and marveling at the car’s ability to bring itself to a stop every time traffic halted. Suddenly an overly aggressive driver tried muscling into traffic ahead of me.

Instead of stopping, however, my big-ticket sedan moved forward as if that jerk wasn’t even there. I slammed on the brakes — stopping just in time — and immediately shut off the active cruise control.

It was a stark reminder that even the best technology has limits and a good example of why drivers should always pay attention behind the wheel. But it got me thinking:

What would’ve have happened if I hadn’t stopped?