Mailing from coast-to-coast sounds like it would take a long time, but there are regular flights cross-country, and the sorting facilities bring mail to the middle of the coast, and then ship it straight across, east or west, depending. This means that the mail has to go first to a central sorting facility.
Truck and bus drivers must generally take a minimum of eight hours off between shifts, and their shift hours are often capped. Airline pilots are required to have 10 hours off between shifts to allow for transportation and rest time.
Employees must receive at least eight hours off work between shifts. This does not apply if the total time worked on both shifts is not more than 13 hours. An employee and employer can also agree in writing that the employee will receive less than eight hours off work between shifts.