One of my part-time jobs is working at a truck stop (console operator, yep its crap), so I see you guys all the time. I always wondered what you could do in terms of lifting.
If you are motivated, get a barbell (cheap one $200 from Gym Direct) and load a heap of cheap plates (say 150kg worth, 2x25s, 20s, 15s, 10s, 5s, 2.5s) and when you stop, just rip that fucker out and do Deadlifts, squats, Overhead presses, rows, curls, triceps extensions, and whatever else you can do with a barbell there is heaps of olympic lifts you can learn. Before you know it, you will be a strong fucker and the other truckies can go fuck themselves if they say anything. Just do them behind the truck wherever you park. Tuff it out and train outside like a beast, even in the rain and shit. Thats what I would do if I were you, you got heaps of storage to carry the weights, all the trucks I see do. Do this on the road and relax with the missus when your at home.
Than post pics so we can be in awe of your beast like appearance in a few months. you would be the baddest truckie out there, and give truckies back their baddass rep every kid imagines you guys to be. Instead of the reality, fat, overworked, underpaid, unhealthy sods. I am serious here, I would do it if I were a truckie.
EDIT: And as Tregs suggests, make as much food to take as you can, shit I do this for myself every week anyway. I cook 14 meals a week to keep frozen so i always got at least 2 good options, add a killer big ass shake to that and your set for the day. (this works wonders, but my prob is sticking to eating them LOL)
Good luck
Graeme