Adapted from a recent online discussion.

Question: I carpool with another young professional about an hour each way into our office. I'm lucky to save on gas, but my carpool companion engages in near-constant texting when it's his turn to drive us. About once a week, I ask him to put his phone down while driving, but I'm met with an emphatic, "I'm not texting! I'm (insert other screen activity here)" or another crack about my own driving habits.

I'm diligent about putting my phone away while driving and very rarely if ever fiddle with the stereo behind the wheel. I'm at a loss as to how to explain exactly how dangerous this is, not just to us, but to everyone on the road. Short of breaking up the carpool, what would you suggest?

Answer: Breaking up the carpool.

I'm all for saving money and gas, but, really? I can't help you if you wrap up your question by ruling out the only good answer.

Maybe we can both get our way when you tell him, "Either your phone goes in the backseat or I'm not carpooling with you anymore" - but he's still going to be a combination of defensive and overconfident in his driving ability, and that's a problem even if he stops texting.

Comment: You might want to ask him if he'd get in a car with someone who was drunk or high. Texting has the same effect. Also consider anonymously calling in his license plate. Texting while driving is illegal in many states and is as dangerous as driving while impaired. New research shows using hands-free devices to "e-mail" orally is even more dangerous.

I worry very much about the safety of our streets if the trend of staying connected in the car continues.

Answer: As do I, thanks. Studies of "inattentional blindness" are (sorry) eye-opening ( They're also hard to forget, since they track whether people notice something right in front of them when they are concentrating on something else - and the most famous "right in front of them" item is a person in a gorilla suit. Which a lot of people miss. To learn more, read The Invisible Gorilla by Christopher Chabris and Daniel Simons.

Question: You're right, my carpool companion is by nature very defensive and overconfident in his abilities (driving and otherwise).

We work two cubicles away from each other . . . and live on the same block. We've known each other casually for years outside work, and I'm concerned breaking up the carpool is going to turn into WWIII both among mutual friends and at work.

Answer: Since you're friends, colleagues, and neighbors (a rock/hard place hat trick, well done!), approach this outside the car, over lunch or coffee. Say you appreciate his friendship and the carpool seems to work out well for both of you, but you've seriously considered pulling the plug over the phone thing. Will he agree to (a) let you hold his phone? or (b) let you drive and just split the gas in a way that's fair to both of you? or (c) offer another solution?

A friendly setting and inviting his suggestions are both WWIII-prevention tactics, as is deciding his ego is not worth your life.