Good question, and I'd be interested in knowing too.
I use a company that collects and discards sensitive documents from my business, and the same guy (driver) has been collecting from my office for about 3 years. He told me a year or so ago that the company uses GPS on his truck, so they always know where he is (and things like whether or not the engine is on, etc.). So, if it does require separate equipment, it can't be too cost prohibitive.