Conclusion
Manholes are in essence man-made holes, Nelson told Live Science, and these are typically made from rotational tools, which tend to make circular shapes. So, a circular shape covering the manhole would be the best fit in terms of functionality. Anything else would be more complicated and less economical.
Additionally, custom bollards can serve branding purposes. Businesses may choose to incorporate their logos or specific colors into the design, creating a cohesive look that reinforces their brand identity while ensuring functionality.