Literally, ttt means Texting + Traveling = Tragedy. "ttt" is what you say when someone texts you while you are driving. You don't want to be rude and blow them off, so you type in ttt. In other words, ttt sends the broader message of "Hey! I'm driving right now! But I'll text you back when I've safely reached my destination." Why ttt? Basically, cause its quick and simple. It allows you to continue to focus on the road, but give a polite response simultaneously.
ttt is best used when at a stop sign, traffic light, or stopped in traffic. Although you are technically still texting while driving, it's minor. It's similar to the flu shot- you need to get a little bit sick in order to prevent getting sick for the season. With ttt, you have a text a little, in order not to text fully.
You are in the car, and your new man texts you and says "ay boo, come over and ill give you a massage."
Yes, you want to go over. No, you don't want to lose your man. But your response should NOT be "coming daddy."
Instead, it should be ttt.
That informs daddy that you are driving and will respond properly when you are done driving and the keys are out of the ignition.
Remeber Folks, THINK SAFETY!!!