I’m not big on spying on teens generally. I think that privacy is important. And by the time they are teens, in most cases we need to trust that at least some of the stuff we’ve said for years has stuck–and we need to let them learn to be independent and make choices without us.

That said, if you have a teen who drives, there’s some spying I suggest, assuming you pay for your teen’s cell phone (if you don’t, I’m really jealous): check to see when your teen is texting. More specifically: check to see if he’s doing it while he’s driving.

I have Verizon, and it’s really easy. With our online account, I can see every call or text anybody makes. I can’t see the text itself (or, if I can, I haven’t figured out how), but I can see when they do it. It’s not even so much spying, because really, you own that information.

Now, you may not know exactly when your teen is driving. This is not a perfect system. But you might catch something–and the fact that you are checking might be enough to make your teen think twice before texting behind the wheel.

A new study in the journal Pediatrics says that half of US teens 16 years and older report texting while driving in the past 30 days. To be fair to teens, we adults aren’t setting much of an example: according to the Centers for Disease Control and Prevention, a third of adults text while they drive.

We all know it’s dangerous, but some of us do it anyway, perhaps thinking that disaster will happen to someone else. And that’s just the thing about teens: they are wired to think that disaster will happen to someone else. Their brains are still developing, and the last part to mature is the frontal lobe, the part of the brain that controls our impulses and gives us some common sense. From an evolutionary standpoint, it’s good that adolescents are willing to take risks; as you start out in life, it’s good not to be afraid of your shadow. But that risk-taking can sometimes play out badly–and often does, when they text and drive.

The same study showed that teens who text while driving are also more likely to do other risky things while driving–like skip the seat belts, drive with someone who has been drinking alcohol or drive while drunk themselves. There’s probably technology to figure that out, too, but it’s not quite as easy as checking your cell phone bill.

If you do discover that your teen has been texting when driving, there should be consequences. At a minimum, there should be a loss of driving privileges. Driving truly should be a privilege, not a right–teens need to understand really clearly how their lives, and the lives of those around them, can be on the line every time they drive.

So set rules for safe driving–and enforce them. And while you are at it, follow them too. Please, don’t text and drive.

This UK PSA from 2009 is very graphic (it’s four minutes long but feels like an eternity, it’s so hard to watch) but it really, really drives the point home. If you watch it with your teen, neither of you will ever think that it’s no big deal to text and drive.

Claire McCarthy is a primary care physician and the medical director of Boston Children’s Hospital’s Martha Eliot Health Center.  She blogs at Thriving, the Boston Children’s Hospital blog, Vector, the Boston Children’s Hospital science and clinical innovation blog, and MD Mama at Boston.com, where this article originally appeared.