The U.S.P.S has hundreds and hundreds of 24 hr facilities. The U.S. Mail is continuously on the move from distribution center to distribution center.
Using your numbers, the whole country would have to work for the U.S.P.S..
LOL!
No, they have 60,000, but only 18,000 (at most) are actually screening baggage--and, BTW, doing so about as efficiently as you would expect federal employees to do anything (including catch illegal aliens). I guess you haven't flown lately, or read the various "TSA SUX" threads on FR.
The U.S.P.S has hundreds and hundreds of 24 hr facilities.
Very few relative to the number of post offices around the country. The vast majority of the USPS operates on a 8/5 basis.
The U.S. Mail is continuously on the move from distribution center to distribution center.
Mostly by common commerical carrier.