I used to work at a company that worked in Logistics. I don't know if it's gotten better, but at least at that point there really was no good solution for multi-modal loads. If you wanted to go truck->train->truck, you were on your own for arranging all of the details. It was far easier to just use a truck from point to point than the other solutions.
It might have improved in the last 10 years though :)
Yeah, railroads were the most screwed up business in the USA for a long while (I got a story about a "missing" soybean car that is truly unbelievable), but they have actually gotten quite a bit better in the last decade. Some of the railroads now have agreements with different trucks to do complete run. I haven't been near the industry in 3 years, but I know it was getting much nicer than before 2001.
It might have improved in the last 10 years though :)