Yeah, they watch the truckers pretty closely. I recall years ago there was some requirement that truckers buy a certain amount of fuel in the state they are traveling through, so that they couldn't fill up in a low-tax state and avoid paying high fuel taxes in a high-tax state. Now I think they have to keep mileage records by state and file tax reports and fuel records to pay the appropriate fuel tax to each state they travel though. I think they do random checks for red dye in the tanks as well.

It must be a real PIA to be trucker nowadays with all the paperwork.

The IRS has a document for truckers about dyed fuel:

http://www.dol.wa.gov/vehicleregistr...dyeddiesel.pdf