where is the bandwidth?

I'm looking for public stats on inter-city IP bandwidth in North America.
i.e. how many Gbps of traffic is there in/out of cities.
I've looked around caida's site and couldn't find anything there.
Telegeography claims to have this kind of information, but they want a lot
of money for it, and who knows how accurate their data is.

Ralph Doncaster
principal, IStop.com