If you're hitting the road this afternoon, there's one specific three-hour window where you might find yourself stuck in traffic and wishing you had left earlier.

Like yesterday. It's the peak travel time for the entire holiday driving period, and here's the heads up in case you want to avoid it.

If you use Google navigation systems you're used to hearing that lady say, "You are on the fastest route and your route is clear." Today she might be saying, "This stinks!  You should have left earlier."

AAA says today (Dec. 23) between 3 and 6 p.m. will be the busiest time on the roads for the entire holiday travel period, which runs until Jan. 3. The traffic will be steady all day though, with the heavy flow starting at 11 a.m.

There will be 100 million people traveling in the US for the holidays, and 90 percent of them are driving. Those numbers are higher than ever.

If you're looking to avoid the rush coming home, Dec. 27 will be the busiest time. At least by then, the kiddos will have some new toys to keep them occupied.

Do you play the license plate game in the car? Finding license plates from all 50 states is a lofty goal to set, and we always run out of energy for it about halfway in. Hawaii and Alaska are tough ones.

Other ideas include the Alphabet Game, the Animal Name Game, and  Twenty Questions.

And turn up the radio!