Now, c'mon, who doesn't stop what they are doing when this one starts in? Since it featured in a popular videogame recently, even the youngsters must know this one...
It is, of course, C W McCall's 'Convoy', title song from the movie of the same name, inspired by the song itself (a most unusual turn of events):
There's actually two versions This is the one that is most often played on Radio Two.
And this is the original theme from the movie, with lyrics adapted to follow the plotline:
And no, before anyone asks - I never had a CB radio!