Indeed. Yesterday morning, while (as already related) out and about, I spied, in Horseferry Road, this long line of buses, trying to move, but failing. In other words, a bus jam:
This was on a Saturday, the weekends being when they like to do roadworks, which means they do things like divert buses from their regular routes. That might have been what was happening here. Or, they were maybe diverting buses from the bottom end of Victoria Street on account of demonstrations happening in Parliament Square.
Both of which circumstances are quite regular occurrences at the weekend. Nevertheless, in three decades of living very near to this road, I have never witnessed such a thing before. Or if I did, I never noticed.