Where is the logic???

Could someone please explain to me the logic behind why Londoners can't seem to walk consistently on the same side of the pavement??? With a city this size, you'd think there would be some sort of protocol to keep pedestrians flowing smoothly. But nooooooo! Instead, it's like being in an ant colony, with people going in all sorts of directions - some walking on the left, some on the right, some darting back and forth to keep out of the way of others. Inevitably, people are constantly running into one another (saying 'sorry' as they walk along). What's with this? Why can't everyone keep to either the left or right so everyone is moving along with no hassle?

In America, it's just a given that pedestrians always keep to the right. Same as on the road. Whether it's on a staircase, sidewalk, hallway, whatever, everyone automatically knows to keep to the right. Makes perfect sense to me. Over here, even though everyone drives on the left, they do not keep to that same logic when walking. Unless there is a sign posted to specifically say 'keep left' or 'keep right', people just go in all directions. It drives me absolutely insane!

On the escalators in tube stations, you'll see signs posted for people to stand on the right so that those who want to pass can do so on the left. Fair enough. (Even though it is completely opposite from the rules of the road - where the slow movers stay on the left so those passing can do so on the right).

I just don't get it. But then again, perhaps this is just another way for the Brits to 'take the piss.' They must get a kick out of seeing total mayhem on the sidewalks (or as they say here, pavements). But that's another gripe for another day. Pavement (to me) means the road, not the sidewalk!