Well...as it turns out I really can't drive 55. It is a pitifully slow speed that is far too slow for today's modern automobiles.
I cruised into Western Pennsylvania on I-70 today from West Virginia and Ohio where I'd had the cruise set at about 72 or so (got 26.8 mpg!!) and I-70 from the PA border all the way to the Pennsylvania Turnpike was 55 mph. That was about 60 miles of torture. After about 20 miles of going 60 or so (this bordered on painful), I couldn't take it anymore. I swear the car was getting pissed off at me, even it didn't like going that slow. So I popped in Sammy Hagar, cranked up the volume, set the cruise at 70 and risked the ticket. Made it out okay.