Why do the sidewalks on USA roads use big, massive stone plates instead of asphalt?

Question

Roads in the USA use asphalt, like every other country.

However, the sidewalks don't use asphalt. Instead, they use enormous, gigantic square blocks of some kind of stone material. Where I live, the sidewalks consistently use asphalt, just like the road. (They are not on the same level, and separated by a kind of long, rectangular stone.)

Why did they go for this way in the USA? What's the benefit of using those flat square rocks instead of asphalt, specifically for the sidewalk? If they are so good, why not also use them for the road as well?

Since they already use asphalt for the road, it seems like it would be the most convenient and logical to also use asphalt for the sidewalk, but they go out of their way to (I assume) laboriously place these plates everywhere for people to walk on.

One thing I remember somebody saying in the 1990s was that he wished that the sidewalks would be like in the USA because they were better for skateboards for some reason, but I doubt that the ones in charge cared that much about skaters...

Answer 1

Slipform paving isn't that big a deal, some basic ground preparation, then follow the line. The contraction joints are added to the wet concrete either by the machine or by workers with hand tools. As the concrete cures, it contracts, and the pavement cracks at the joints. Concrete is much harder and holds up to edging and other abuse that asphalt simply can't handle.

Concrete lasts much longer than asphalt, and sidewalks are very expensive to replace once all the landscaping is in, so the more durable option is usually the way to go. Asphalt road surfaces can be repaired much more cost effectively. You do see some asphalt sidewalks where fussy landowners aren't an issue, such as at schools and business parks.