I know very little about this profession, but have always liked lorries for some reason (had a truck stop of all sorts when I was little) and know a few drivers/managers.
What about approaching a respectable haulage company and asking for a 'work experience' equivalent and spend a couple of days with someone to see if you like it (assuming the company don't have insurance issues). I would say Eddie Stobart, but I heard they relocated their base to Europe for cheaper diesel, and run rigs with huge tanks coming across here.
I did drive a Peterbilt 3 trailer road-train in the Northern Territory, Australia (hitched a lift from NSW to NT) only for a few miles - but it was amazing, as were the cabs. The drivers have games of how many kangerooo's they run over, seem avid talking book fan's, and all are high on something, typically speed (even get asked in interviews on what they use to stay awake!).
I would say that if your a family man, not to follow this career though, as you're away from home for ages.