To begin with there is still quite a number of contractor employed drivers who still while considered to be blue collar hourly wage earners do not punch a clock . They are on salary. Now as Orion pointed out when you enter the building you are considered to be "on duty" but few actually enter for the record the time they entered the building as their official "on duty" time. It is often a lot later in order to stretch out their HOS because there is still a huge number of routes out there that are HOS maxed everyday.
I'm quite certain that you Express and UPS guys would be shocked at the number of decades old wage and hour violations that continues to this very day. And is entirely in keeping with the abusive poorly designed cobbled together setup that it remains today
Rest assured they will be a day of reckoning for Fat Freddy's hiding in plain sight goldmine .