Hi Lagunaboo and DirtyDeeds, thanks so much for the info!
Here in Minnesota (I can't speak for the rest of NA), a lot of carpenters who are specialized, such as new-home builders, can get away with a pick-up with one of those cross-bed tool boxes, because typically all they need to bring is a level, circ saw, tool belt, and a few other assorted tools, their boss supplies the big air compressor, etc.... I work for a moderate-sized, mid- to high-end remodeling company, and the vast majority of my coworkers (we employ around 20 carpenters) drive pick-ups. The majority of those drive 1/2 ton trucks, there are maybe six who drive 3/4 ton, and two who drive the enormous 1-ton Chevy, with the 4-door crew cab, 8' box and dually tires. A few years ago approximately 1/4 of our carpenters towed trailers of various sizes, from smaller single-axle units all the way up to 8x16 twin axle V-nose behemoths. That practice ended when the guys who were towing using 1/2 ton trucks had to replace their transmissions, one guy who towed a 8x16 was promoted to project supervisor, and the other who towed a 8x16 lived approximately 50 away from our home office couldn't justify the convenience over the fuel cost to tow it 100 miles round trip every day. BTW, in the past few years he has since changed his tune and is trying to negotiate to repurchase his trailer....
All of my coworkers have toppers on their trucks. In addition to all of our 1/2 ton+ trucks, one older carpenter somehow gets away with driving a Chevy S-10 (loaded to the gills), another drives an old Dodge mini-van (again, loaded to the gills), and finally another carpenter drives a 1-ton Dodge Ram Van.
For our company we tend to carry most, if not all of our tools with us daily. While most of the time we can anticipate where we will be working and what we will be doing for the next week or so, each crew of carpenters (we have three in my crew) typically has 3-4 projects going on simultaneously, and theoretically we are expected that at any time we should be able to pack up and leave, say, a framing job at noon and drive to another job to do some quick trim work, fix a roof, drywall, etc...