Aesthetically, black bollards contribute to the overall design of urban areas. Unlike other materials that could clash with the environment, the neutral color of black allows these structures to blend into their surroundings while still serving a purpose. This subtlety can enhance the beauty of public spaces without overwhelming the intended design. Many municipalities take this opportunity to use creatively designed bollards that reflect the local culture or history, turning them into art pieces that enhance the character of the area.
Environmental Considerations
slim garbage can with lid

After knowing the loading capacity then surely you can come up with what material suits best for your cover. There are lots of materials available for manhole covers but the most common are cast iron, concrete, or the combination of the two. Whether you will choose the typical composition or on the newly manufactured covers, just make sure that this is suitable and durable enough to serve the purpose of your hole requiring less maintenance.