I am a freight broker. I arrange the transportation of merchandise from the manufacturer to their customer. I do not own any trucks, I am a middle man to negotiate pricing and service for my customer.
Please note that this logo will be faxed constantly, so I can't have too much of a detailed design that comes out as a black splotch on a fax.
Edit: One idea I had is with an outline map of North America. My service is mainly Canada & USA, but I can also service Mexico so a map including Mexico could also work.