The reasons for making the access tunnel beneath cylindrical in shape are actually far more compelling (remove less material and create a stronger hole).
Nevertheless, rectangular manhole covers are pretty common.
Nevertheless, rectangular manhole covers are pretty common.
I never claimed the market was perfect. I find that perfect omniscient markets a terrible assumption to base analysis on.
The combination of superior cover safety and superior tunnel structure are pretty compelling, but not everyone chooses the optimal solution. That's just not how humans operate.
Nevertheless, rectangular manhole covers are pretty common.