Internet routing is dynamic, and is supposed to be resilient: if one route fails or becomes congested then packets will be routed another way.
I once saw a route in London's Docklands go down, and packets from one data centre in London were being routed to another data centre in London via Amsterdam. The net kept working, but it was noticeably slower.
FWIW, the routers you noticed are in the Maylands and Centro data centres of Gyron Internet Ltd (who own the AS29017 network), both in Hemel Hempstead. You can tell quite a lot from a traceroute
Anything about use of this forum : NOT about cycling