Seventy-eight wasn't fast enough for this sheriff's deputy, so he got into the Carpool Lane for 2 or more drivers, though he was alone. After he hit 83, I couldn't keep up in heavy traffic, but I submitted a formal written complaint, as I have many times before.
Do your part for safer highways.
Rest assured, you will never get a ticket for this. I have been doing it for 30 years.