Chesterton's Traffic Lights¶

This is about an instance of Chesterton's Fence from my life, that I finally solved today (23/02/2025).

I like the parable of Chesterton's Fence. It requires humility and respect to look at something in the world that inconveniences you and say "I don't understand, but I think somebody else does or did, and they might know or have known better than I do".

There is a road intersection just downstairs from my condo, that I have seen and crossed thousands of times in the 5 years I've lived in the place I currently live. I noticed early on during my time here that when crossing on one side of the intersection, the green light for pedestrians lasts longer than when crossing on the other side, despite no difference in the flow of traffic across the two different sides. I've often thought to myself, "That's annoying and daft, why isn't it just the same!"

Today I finally came up with a coherent explanation as to why they aren't the same! On Sundays, the foot traffic for the side of the intersection with a shorter pedestrian green light is significantly higher, and if the pedestrian green light lasted any longer, the number of people who would be able to leave one side of the crossing would be too great for the size of the island they cross over to on the other side, and they would spill out into the road, causing a hazard. The other side of the intersection doesn't have that problem because the foot traffic on that side there never gets as high.

Now that I think I understand why the difference is there, I can in confidence propose how it could be better: The duration of the pedestrian green light should only be shortened on Sunday, rather than on every day. If you asked me before today, I might have said "Just make the duration the same!", and that would have been a hazardous mistake. I've always suspected that there was a sensible reason, and today I finally came up with something I think is really plausible, and I'm happy about that.

Created on 2025-02-23

Updated on 2025-02-23