[G-CPTN]

Watching 'Big Rig' I have so many questions about the sort of work that he appears to be doing.
I don't know whether he is truly a single owner driver or whether he works for a 'line', but so far he seems to be moving trailers between unbranded sites. Of course he probably works through an agent (he seems to know his moves a couple ahead) but has anyone done this sort of work (in the US) - or even in the UK? Security must be an issue (though he might not be moving valuable goods) - both en route and at stops and changeovers. What stops unattended trailers being 'lifted' from a vast parking lot? How does a driver ensure that he has collected the correct trailer (and delivered it to the precise location)?

Many of the main routes seem to be toll-roads. Are vehicles fitted with transponders (he seems to pass through toll-booths with only a brief hesitation)? Are all toll-roads in a region operated by the same agency? (He moved from Pennsylvania Turnpike to Schuylkill Expressway to Wait Whitman Bridge (all toll roads) and then onto the N-S Freeway without apparently stopping or passing noticeable toll-booths.

I've already posed the question about drivers' hours rules in the Big Rig thread - but feel free to answer here.