Van Tapes Calculator
Basically, this tool calculates exactly what that bandwidth actually is. It does take into account the carrying capacity of the vehicle. For example, most vans won't be able to carry more than 2500lbs of hard drives, which works out to a surprisingly low number of hard drives.
I probably could add in something to calculate the latency. See here for some comparison of bandwidth speeds.
For some reason this is broken in Chrome... (turns out that I had variables/prototypes named media which is some sort of reserved word, changing the names cleared it all up)
# of Tapes:
Drive Time (hours):