The 20 mph thing is happening where I live as well (in parts of Utah), and it's being widely ignored. I don't speed in general. I especially avoid it in places where there may be kids or pets around, so I end up with some big penis truck tailgating me when I'm on those 20 mph roads. It's so frustrating because these people haven't seen what happens to pedestrians when they get hit.

Content warning, I'm going to describe an accident I saw. When I was 16, I saw a man step out onto the road about ~50-75 feet in front of a car moving at ~40 mph. The pedestrian didn't look before he stepped out, and he wasn't anywhere near a crosswalk. He looked like he was coming from a construction site and was probably just tired. Nobody was speeding and the driver had pretty admirable reflexes (I could hear the juddering from his ABS brakes).

Even with that, the guy got hit before the car could come to a stop. I saw him fly back several feet, and the thing I'll never forget is the way his head fucking bounced as it hit the pavement. The amount a person's head will bounce is just fucking awful. I'll never forget what he was like afterwards. He had a heavy concussion and a huge bruise on his head. He could barely speak and he kept pawing at the air, like he was seeing something. He kept trying to get up, to the point where someone had to hover over him to stop him from moving (he might have had spine damage). He got hit so hard that to 16 year old me, he turned from a person into an injured animal. It felt like the spark in his eyes got kicked out when his skull hit the ground. It was terrifying to see someone get their... sapience? Maybe there's a better word, but see someone get their sapience smashed out of them.

Like, the guy I saw was lucky. The driver wasn't texting and slowed down considerably, and there were multiple first responders with some degree of training. He wasn't crushed. He didn't go under the car. An ambulance was there within 5 minutes of the accident. He probably lived, and he probably didn't end up with permanent brain damage (according to the EMTs). Every time I drive through a neighborhood, I imagine a kid running out from behind something, right in front of my car. If I'm going 30-40 mph, that kid's head is gonna be doing the asphalt bounce. If I'm going 20 mph, that kid is going to shit their pants when my 3000 pound death machine stops a foot away from them.

I just wish I could make these people understand how fucking awful it is to be hit by a car. It's been more than 15 years since I saw that happen and I still feel ill when I try hard to remember it. I can't imagine how bad it feels for the driver, and how much, much worse it feels for the guy who was hit.