The previous context was, "Why on earth would there be a 40mph road next to a school"
The surrounding context was a comment about how the flashing light WASN'T on and how the speed limit was, per the sign, only enforced when the flashing light is on.
So, "why would it be 40mph?" because it's a stroad - a main thoroughfare through a town that's like maybe 5 or more lanes wide (including both directions and the 'turning lane'.
There's value in asking the question why there's such a wild variance in speeds between "normal" speed and "school open/close" hours, and that's a useful question to ask and likely comes down to the car-centric politics that filled the United States for well over 50 years, and will take a very long time (and a lot of political clout) to fix.
Depending on the size of the town, that may also, literally, be "the only road" that makes sense for that school to be on, so you have conflicting interests of a major, high-speed arterial road as well as the safety of children during particular hours.
And to add *even more* to that, if you're going 40 and expect the speed limit to be 40 and everyone around you also expects the speed limit to be 40 (because that's the posted speed limit, and the sign isn't flashing), then you going 20 creates a 20mph differential between you and the rest of the traffic around you and now you're *going* to cause an accident.
Have you seen modern US schools? They're basically setup like prison yards because of all the school shootings. There's no way the kids are going to run into the street without first going through a parking lot (and, often, a line of bollards).
On the bright side, there's zero reason to slow cars down when kids aren't being actively picked up or dropped off.
(Not that there was a reason to slow the cars down during off hours in the past, since the law has always been "When children are present" in places I've lived, which is good enough.)
To be fair, US schools have been very 'shaped like a castle with walls' for longer than school shootings. When I was in school, there was no way to get to the road, outside of entering and exiting the whole compound.
Your comment seems to imply that parking lots around schools are somehow strategically positioned to prevent school shootings? I'm not from the US but I'm intrigued by how that would work.
They retrofitted fences in the last decade or so. The only break in the fence is usually near the administration office / pickup / dropoff zone, which is generally next to the parking lot.
It doesn't actually prevent school shootings. There were 330 in the US last year; 349 in 2023. They're also adding cameras, weapons detection systems and "resources to address students’ emotional and mental well-being"
Across the US, only 70% of students live within 3 miles of their school, and only 20% of students are within 1 mile. Toss in weather, carrying supplies for after-school activities, tight schedules (e.g., going from some before-school activity to the actual school building), a general fear of kidnapping, a car-centric culture, and the fact that buses are cheap and school dropoff is often easy to squeeze into a parent's schedule, and you'll find that various forms of driving are extremely common.
It only works if you are lucky enough to live the side of the school with the pedestrian entrance. A colleague lived near the side with car entrance so walking their kids to school required walking the extra 1/2 mile around the grounds as they weren’t allowed int he car entrance.
I am suggesting that having a major road that suddenly drops to half speed, without significant signage, then speeds back up is bad, yes. That's just a form of speed trap.
I'm aware of how natural speed limits work. And my point is these are frequently major roads that are miles long, not residential streets. Major arterial roads, sometimes state highways.
In the kinds of places I am thinking about, step one is choosing not to build directly on a major road, miles away from residences. Which is not always realistic, when residences are miles apart from one another. The decision for safety needed to be made about a dozen decisions ago in those situations. What is left is busing kids home.
Enforcing safe speeds a few hundred meters around a school doesn't help much for biking or walking when the rest of the infrastructure remains deadly. Placing the school there is just a bad choice if you want children to come to school independently from their parents.
