Just thinking out loud
1- could it be something to do with what passes over them.
millennium = footbridge
Hungerford, London, Blackfriars = Foot & Rail
Waterloo = ?
2- Maybe a song link.
waterloo = ABBA
Millenium = Robbie Williams
London Bridge (is falling down) = nursery rhyme
Hungerford & Blackfriars = ?