Ad campaign: Long haul

The client is a trucking company specializing in long hauls (long distance transportation). They're looking for a photo they can use for various purposes including their newsletter, their web site and on leaflets. The image should be bold and really speak to the idea of long haul trucking. They do not necessarily need a photo of a truck as they're open to the idea of something more conceptual if it gets the point across. What they do not want is an image with any sort of brand easily identified.