on a 2 kilometer long promenade i meet the only 4 people - 2 couples which come from opposite directions - just when i want to overtake the couple in front of me (so that all 5 of us meet at the same spot), otherwise the promenade remains empty for the rest of the walk/ride.
or if i go by bike a 4 kilometer long street, the probability that two cars from different directions pass each other exactly in one of the 3 tight spots seems excessively high while the chance that i do not meet any other cars during this ride is also very high.
i pay attention to it for about 3.5 years since it happens to me as good as daily, too often in my opinion to be able to explain it statistically (and also too often to explain it with selective perception).
is there a name for it, how could that be explained or described mathematically?