Mousetrap: That just means that the 17th hop on your way to BrainKing at that particular time was a host with the name PO8-0.prg-001-access-1.interroute.net, and that it took 55ms to send a package to it and receive an answer. This is obviously taken from a traceroute output ;-)

That traceroute thing is just to get a rough estimate of a) how many gateways are passed on a package's way and b) which networks usually are passed. It's not at all guaranteed that the route will always be the same (it is in fact very unlikely that your package will go through PO8-0 every time).
Interoute.net belongs to Interoute Communications in London. There's not much more you can learn from that line...