LA is fortunate in that it doesn't suffer from freeze/thaw cycles and can put down a lot more concrete without worrying about expansion/contraction and water ingress.

I've noticed that a fair amount of concrete sidewalk in Los Angeles appears to have been poured when the neighborhoods were first developed (as in post-WW2) and haven't been removed or updated since then (at least based on the date/contractor stamps). Again, the lack of freezing weather, wide streets that don't necessitate parking/loading on the sidewalk, and fewer tree roots to uproot/disturb the gutters and sidewalks means that the original infrastructure is still in use.

More to the point - creating curb cuts is more than just customizing concrete forms. Oftentimes you'll need to regrade the surrounding area to reduce slope, move any in-ground utilities, and revisit any other updates to building codes (such as the bike lane stuff mentioned in the article). Not everything in/under the streets is owned by the same city/county/state/federal department/private org so that further complicates the work.

If only the real estate speculators that settled this swampy valley had considered this stuff in the early 20th century...

> LA is fortunate in that it doesn't suffer from freeze/thaw cycles and can put down a lot more concrete without worrying about expansion/contraction and water ingress.

The freeze thaw cycles more impact the asphalt. Basically, wherever there is a joint that has been improperly sealed with tar, or the asphalt cracks due to overload - e.g. from heavy vehicles in general or especially surrounding bus stops due to the force of buses accelerating in the summer, when the asphalt is softer, you get water seeping through into the asphalt... and when it then freezes, it expands, making the pothole worse with every cycle of thawing and freezing.

That is why it is so important to properly repair potholes. Some youtubers have made themselves infamous by fixing potholes themselves, but they use non-melting ready mix... that works in a pinch to make sure that vehicles don't get damaged, but you will need to rip that out to the foundation, fix the holes with gravels, compact that, place proper hot molten asphalt, compact that, fill again and compact, and then seal the edges with tar. Otherwise the ready-mix will disintegrate over time and you'll end up with the original pothole, or with an even worse one if you have freeze and thaw cycles.