The United States Postal Service have been cutting the fat. The RCA's are not consider career positions. I had a RCA tell me she has been a non-career (permanent temp) for nine years, they are one step from hostile, due to the lack of hours, and do not have medical insurance. Delivering mail is very stressfull because of the time constraint put on each carrier. This may be the reason why some videos have been posted online throwing the mail away. Supervisors are nasty! They expect you to get out and back in withing 4 hours or you get them in your space talking trash. You have to case (put the mail in slots, organize boxes afterwards, and pull and load the mail & boxes into your truck (very stressful, and boxes can weigh up to 50 or more Ibs. In Texas it's hot and the trucks are made to be uncomfortable, with only a fan if that works, so it's a tin can. Try it and then talk about carriers, I did and I' m done already!
If you can speed deliver you get paid for the route (9 hours or so) instead of actual hours.
If you take longer then your route is listed to take you still get paid the same amount, can be strenous, and dangerous in that truck.