Admit it.

You've done it.

You've been driving down the side street (and yes, the highway as well) when your phone, blackberry, or whatever you use to call and text with goes off.

You immediately grab it, even though you are driving in traffic and really shouldn't.

It's a dangerous and terrible habit American drivers have developed.

The folks at Car and Driver Magazine have now documentedjust dangerous it can be.

Rigging a car with a red light to alert drivers when to brake, the magazine tested how long it takes to hit the brake when sober, when legally drunk at .08, when reading and e-mail, and when sending a text. The results are scary. Driving 70 miles per hour on a deserted air strip Car and Driver editor Eddie Alterman was slower and slower reacting and braking when e-mailing and texting.

The results:

Unimpaired: .54 seconds to brake

Legally drunk: add 4 feet

Reading e-mail: add 36 feet

Sending a text: add 70 feet

When I took the test for reading e-mail or texting, I was just as slow to react. On average, it took me four times longer to hit the brake. Mike Austin at Car and Driver told me in blunt terms that I was "way worse" than the average driver.