location of the al qaeda's most active branch. airports and train station in the united states on high alert. officials are beefing up peak screening ahead of the hole. aaa reports 47 million americans ll travel more than 50 miles. doug is. >> reporter: that number is remarkable given the terrorism threat, as is the number of americans expected to fly over the 12-day thanksgiving holiday. 25.3 million passengers according to the trait group, airlines for america. the highest number since the great recession. and what makes it remarkable, at least in part, is that americans have become aware of the limitations of the tsa, in testing last may, contrabands, including bombmaking material, got through security checkpoints at a number of different airports, 95% of the time. a second round of testing last