Is it possible to stay healthy on a road trip?

I'm really excited that in a couple of weeks I'm going to get to travel with Paul and his band while they go on tour for a week around Texas. I love to travel and see new places, their music is awesome and they're a great group of guys so I'm looking forward to it.

However there is one aspect of travel over here which I find more difficult than anywhere else in the world. I've travelled quite a lot. I even gave up my job once to go backpacking for a year so I find it surprising that this element of travel still causes me problems.... food and staying healthy on the road.

When I was a backpacker I was younger and I didn't really care what I ate. My body just seemed to deal with everything... though in reality I think I was quite a few lbs heavier in those days too (probably something to do with not caring about what I ate!). In the last couple of years since I started running I've been much healthier. I'm more aware of what I'm putting in my body and often I physically react badly to an unhealthy meal.
In England I have a fairly good grasp on how to stay healthy when I'm away from home but America is totally different. It is the world of fast food, drive thrus and junk food that is guaranteed to make me feel (and look) like a slug.

Although I've learned which are the 'healthier' options on several fast food menus and learned that Subway is my friend, I'm interested to know what you do to stay healthy on the road.
Which is your favourite energy or cereal bar that is fairly balanced nutritionally? I'm a monster if I don't eat for a long stretch of time so I'm hoping these will save me from dashing to the sweet isle when we stop for petrol! I'm also still not running due to my knee so I'm keeping a keen eye on my relatively small calorie intake (boo)
What do you do to avoid eating from fast food restaurants for breakfast, lunch and dinner when on the road for a week? I should clarify I don't think I'm going to be able to chill food or have ice packs for a cooler as I don't know the facilities in each hotel we'll be staying at. If there is anything I can get before I go (online or in Walmart) that would be preferable. Any suggestions for fresher food along the way they could do with being from places like Walgreens rather than dragging the band off to the supermarket while I do a shop ;)
If you have any ideas I appreciate ALL the help and advice you can give.
Thank you