It's not the employee's fault if a restaurant is "dead" for an evening. But the employees are required to be there, and thusly, are paid.

Same here. If the truck driver was free to go home, or whatever, sure dont pay them. But traffic jams are in transit between places they are told to go. It doesn't have to be the "fault" of the employer. But the employee is captive, and working, and absolutely should be paid with regards to time.