 This as tens of millions take to the skies and roads ahead of the July 4th holiday. CBS's Chris Van Cleave. American, Delta, and United all expect to fly a record number of passengers, more than 18 million over the next 11 days, with Sunday, July 7th, likely to be their busiest. The TSA is poised to screen more than 3 million people for the first time ever, and that could happen any day now.