"To the extent that it's already being implemented, who says it isn't working?"

I think that would be self evident in the high number of large vehicles right? Is there any counter evidence?

"So? Regulation is often a compromise."

This seems pretty flippant. We could use this same logic for any number of good or bad policies. Eg not everyone can afford college - so? Doesn't seem like strong support.

"I think this is pretty obvious: they're a necessary component of our economic apparatus. A shiny new F-150 with an empty bed and truck nuts on the back bumper isn't."

Do you have any data to back that up? The people I know with trucks tend to use them in ways that you can't use a car. Without data my claim is anecdotal - your's seems to be a stereotype.

"Reducing freedoms isn't the purpose; saving lives is."

If that's true, then show me the data. Show me why this is the only way.

"Should I be allowed to drive as fast as I want wherever I want just because I want to? No; roads are public infrastructure, and we regulate their use for the public good."

This is a very different situation and it's disingenuous to use that as an analogy. One is about behavior, the other is about a categorical ban. One has data supporting it, the other one does not. In fact, speed is a bigger factor in crashes than vehicle type. Why not limit everyone to 25 mph? That would be more effective than what you are proposing.

"I would expect this to be a change that takes decades to unfold. But, surely, you aren't claiming that consumers aren't affected by advertising?"

I'm claiming that there is little to no influence on vehicle type. Brand, sure. Do you have any evidence that it influences type and by how much?

"I expect cultural factors are to blame for our obsession with large vehicles (that, as you say, doesn't seem to be shared by the Europeans). So, given that they seem to have achieved a significantly lower road fatality rate per capita than we have, I would suggest looking at their safety regs and synthesizing what we learn there with our own needs in implementing regulation targeted at improving road safety."

The major difference is the stringent driving test. It's not just fatalities, but accidents in general.

"This isn't germane to my point."

Then why bring it up?

"I'm suggesting that we start with "basic car" to establish a baseline for safety, based on certain basic and plausible assumptions about low mass, low bumper and hood height, etc. being safer. From there, we can evaluate the safety of other configurations. This will also give us the chance to test our initial assumptions about what configuration is safest."

You seem to also be saying that you want to ban, or regulate out of existence, many vehicles (as states in your prior comments).

"When they cause thousands of preventable deaths, I certainly do have a bias against them in certain contexts."

Do you have data to support this? Thousands seems very overdramatic when there are 30k fatalities overall per year. Again, if you're talking preventable deaths, then why not focus on low hanging, universal fruit of increasing driver testing or decreasing speed limits?

"Is it worth Thanos-snapping every vehicle in existence out of existence right now, all at once? I think the suffering (total logistic collapse) that would result from that action would far outweigh the preventable deaths caused by large vehicles in our current configuration of reality."

It would be a transition, not a sudden thing.

"So--in practice--we will have to perform some good faith cost-benefit analysis rather than rushing to absurd extremes, won't we? :)"

That's my point with your extreme position without any data supporting it. If you take into account all the saved lives from reduced pollution and increased physical activity, then my suggestion doesn't look so absurd, right?

"I have to wonder if you have any idea how complicated regulation gets because it has to function in the messy real world."

I do.

"Or is it your position that if I can't cover every corner case of what would necessarily be a sprawling, thousands-of-pages sort of thing in my HN comments, it's infeasible in practice?"

It is feasible to convey your point that exceptions would exist instead of waiting several responses.

"To the extent that they actually do have any meaningful restriction of aftermarket mods, enforcement seems to be laughable--much like driver licensing."

Then why not enforce the current restrictions and see where we stand? Iterate.

"Check OP's link at the top of this thread for some, and Google for more. It is not hard to find."

I did, but there's nothing showing a significant difference. Most of that analysis was looking at ownership rates of vehicle types and overall pedestrian fatalities. Not especially stringent. On top of that, we are talking about around 500 deaths per year. You could make a bigger impact by banning many other things, like pools, alcohol, etc. In any case, this doesn't show data on non pedestrian crashes.

"If you're talking about modifications specifically, I don't think the fact that nobody seems to have gone looking yet is a good argument that nobody should go looking. Do you?"

I'm suggesting that restrictions be based on data with a clear and compelling benefit, which you have yet to provide.