In the U.S. we have a bias toward passing on-coming sidewalk pedestrians on the right. I’ve always attributed this to our decision to drive on the right side of the road. Naturally in the U.K. I assumed that since they drive on the left, they must generally pass each other on the left on the sidewalk as well. In Oxford at least, this doesn’t seem to be the case. Collision avoidance is entirely ad hoc. I don’t know if this is true for the rest of the U.K but if it isn’t then it may be due to the incredibly diverse population in Oxford. There are people from everywhere here.