Darth Vader on two wheels

But there wouldn't be big or awkward junctions if there were no cars.
But there are cars, so this is pointless.
Just my personal view is that lights are for cars and are more of a guidance for cyclists.

Its really good when light fail, and then people in vehicles actually HAVE to look out and communicate with each other, really find it amazing how much energy is wasted on sorting out junctions when people can actually as you suggest work it out fairly equitably when given the chance. then of course this is london, my friend and anything can happen.