"I guess a significant proportion of trucks spends more than half their time on interstates." I would have to look at actual figures, but my gut feeling given

"I guess a significant proportion of trucks spends more than half their time on interstates." I would have to look at actual figures, but my gut feeling given the truck routes around us is that might be suspect. I'll echo galdosdi on the rest, the interstates aren't exactly easy.