If the package volume is down why do I see rental railbox trailers still being used? I was on a major east-west interstate the other day and in approx. 50 miles the 22 east bound feeders that I saw, 6 of the were railboxes. I realize that there is a need to balance equipment but what is the cost of using a 45' railbox? Any load planners or schedulers out there know the answers to my questions?