Heavier cars are safer for their drivers, but far deadlier for everyone else

You are right. And the simplest solution to this is to increase the cost of fuel /energy (typically by increasing taxes on it). This automatically directs us in the right direction. More fuel efficient cars. Or public transport and bicycles instead of cars.

Same with electricity. It also has to cost more. Right now electric cars are not very good for the environment either. They are bigger than necessary and consume too much electricity.

Unfortunately governments have never managed or dared to increase it. And unfortunately it often creates a lot of tension among the population.

The population likes to complain that it is the banks which are to blame (because the invest or lend to oil companies) or that the oil companies are to blame. But it is the people using the cars (unnecessarily big cars) which are to blame. And the politicians which do not enforce a higher cost on burning energy, by not increasing taxes on energy usage.

Due to the war in Ukraine we finally see some movement on this and it will become more important with energy efficiency and finally we see even governments send out flyers and inform of methods to save on energy. Why did they not do that before? There has been those COP meetings with presidents for over 20 years, but they have not been capable of doing the most basic things because they are afraid of affecting growth.

Unfortunately they don't understand that a fuel efficient car can transport as much as a non-fuel efficient car.

While I generally agree with your sentiment, I think the health insurance example is not a good one. There are several factors that are wrong with it, for one people with insurance have advantages over people without, so you are creating a system where your access to healthcare depends on how much you earn. Secondly, it essentially creates an artifical market for insurances with pretty much guaranteed customers, the insurances don't even need to offer that much over the state system because it's cheaper anyway. If you want have the universal health care not be as loaded, simply raise income/wealth/other taxes and use that funding to prop up health care. That's a much fairer solution.

Isn't it relatively easy to bypass? The legal owner and the person that actually uses the car might be different people. E.g. a family might swap cars to lower their taxes.

Doesn't it result in a similar scenario? Rich people can still opt to drive heavier cars and even fewer poorer people still cannot afford them.

I get that adding taxes is less fascist than straight bans, but it also raises inequality.

There's a tweet I read that says something along the lines, "as long as any change, despite how beneficial for most poor people will hurt some poor people, it is the progressive position such change is bad. From that the progressive position is keep everything the same."

The irony is of course that poor people disproportionately suffer from car fatalities, so "change" is already being wrought on them by the increasing size of cars and increasingly more expensive and difficult car culture. They just lack the voice (or awareness really) that middle class people who want to protect their position and privilege do, and the latter do not hesitate to use the poor as props whom they otherwise have contempt for the moment they need relief in other areas.

They'd drive them a lot less with European levels of gasoline tax.

And would be eventually priced out by something like this.

I worked in the trades for a little and primarily focused on tile and odd carpentry/framing jobs when someone called out.

Nearly all of my material got delivered in one day, but the job would continue for weeks afterwards. I would drive my Prius and catch flak from some guys until they realized I could do everything they could do in their light duty trucks and get 3-5x the MPG. I can carry a handful of sheet goods, bunch of studs, hardware, etc. If something needed more than that having it delivered made more sense as my time is more expensive than the delivery driver’s time. In the rare occasion I was slow we would rent a Home Depot flatbed truck for a couple of hours.

I think most people overestimate how often they need large trucks for work and could get away with something much much smaller.

> 99% of trips can be done in a 400kg LEV or even a 30kg single occupant vehicle, but some tasks legitimately require a 3 tonne truck.

If that's the case, it might be more economical to do the majority of work with a smaller vehicle, and rent the larger vehicle when necessary.

Ah yeah we definitly live in times where humanity can afford people who rationalize their behaviour like you.

I haven't had a car in 10 years now and guess what I do with the 1% of tasks I cannot do with the bicycle or public transport? I rent a transporter. Like any responsible inhabitant of a dying planet would.

1% of 365 days is less than four days a year. So you say me you buy and drive an expensive, heavy and polluting vehicle that consumes a lot year long because you barely need it four days in the whole year.

Vs renting a generously sized truck when you really need it ?

It’s not worth it, either for you and for everyone else.

Then hire a 3 tonne truck for those 1% of trips when they happen. People acting like "oh because I need it for 1% of trips I guess I should just drive it for all trips".

Yup, things like 8L Lambos are ULEZ compliant! Giant Rolls SUVs, also compliant.

What a fucking joke.

Height above the ground matters too: high cars hit pedestrians more on the chest, lower cars hit the legs.

And high cars can roll over lower cars, making the deformation zone have no effect.

Interesting anyway about weight.

I'm thinking high cars should be forbidden ... Unless in terrain on the countryside.

EVs could be regulated (or incentivized) downards too, there exist much lighter EVs already.

In Europe there are some sub-500 kg cars (eg Renault Twitzy). Not that this should be the limit necessarily, but there's plenty of room downwards in the design space.

> streets are being narrowed

I hope this works, but I've noticed more wide vehicles in my neighborhood parking with two wheels up on the sidewalk, like this.

https://imgur.com/a/v0w3FMM

Streets being narrowed doesn't help as I myself have experienced the rise in SUVs in London, which has some very narrow streets :p

In fact, my driving experience so far is that smaller cars are more likely to wait if it's too narrow, but people in larger cars barrel on thru bc they know that they'll intimidate drivers on the other side.

Being a cyclist in a crash will be like swatting a fly against a windshield.

But I guess that in the future, no one will drive themselves anyway. Whether due to automation or cost.

...until you have to exist outside of a car, then it is downright terrifying (and extra deadly).

Yeah i'd love to drive a battle mech that'd be amazing. And imagine how jealous the Moms down at soccer pickup would be!

Agreed, there should be a 5 year refresher. There are similar refreshers for other life-affecting licenses (medical / first aid licenses for one).

Requirements to drive in a car dependent region have to be minimal. Lots of people shouldn’t be on the road, but there’s not exactly room for them in Manhattan, SF, or the handful of other areas where you can live without a car.

LOL and then later on a professional driving a tractor-trailer unit who is able to hold the line perfectly. The skill gap is enormous.

Well, I live in the burbs and have a kid in his carseat in the back, plus stroller and groceries. Not to mention I'm a rather large man and when we last looked for cars I literally couldn't fit into a lot of them, I need more space. Even more, great gas mileage and reliability, and very safe. "Compact SUVs" or whatever they call the Subaru Forester now and it's ilk are exactly perfect for my family, especially with another kid on the way.

I'd like to see a source for that. It's wide, but it's still within federal limits.

> Turns out the momentum from higher mass and the increased friction from higher mass balance exactly.

yes, in the spherical cow sense, but this isn't at all true for real life vehicles and tires. the weight of the vehicle does have a significant impact on traction, here's a quick video explaining tire load sensitivity: https://www.youtube.com/watch?v=kNa2gZNqmT8

related to the above issue (and as GP mentioned), the high CoG of an SUV also poses challenges for braking performance. you want all four wheels of the vehicle to have roughly similar braking force. obviously the front wheels are going to contribute more to braking than the rear, but you don't want a huge disparity. this doesn't matter so much for the abstract question of "how quickly can a vehicle stop?", but it matters a lot for the practical question of "which direction is the vehicle facing?" if the rear wheels are contributing much less of the total braking force, the car is likely to end up sideways. this is bad if you want to do something like "remain in control of the vehicle" while braking.

GP didn't claim that braking distance was larger because of higher mass. Rather, because of the higher centre of gravity the ABS has to be calibrated differently, leading to weaker braking, thus larger braking distance.

I have no expertise in this, but seems prima facie plausible.

Where does vehicle mass come into play when cars have ABS and thus it's always the brake pads stopping the car, not the tires?

I think you are looking at this wrong. It should be surface area of rotor/brakepad interface per lb of vehicle

That would be true if your wheels instantly stopped turning when you applied the brakes.

The limiting factor for braking isn't the friction between your wheels and the ground, which is weight-dependent, but the friction between your brake pads and rotors, which is not weight-dependent.

I recall learning this in a class on the automotive industry about 20 years ago. We learned about unintended consequences that caused the US automotive market to favor SUVs (see the Chicken tax [1]), and some of the downsides of SUVs.

My recollection is that SUVs have longer stopping distances because the ABS has to pause braking more frequently to avoid instability or rollover. It's possible, as another commenter suggested, that I'm recalling ESC, but that wasn't very common in the early 2000s. I think it might have something to do with the fact that the nose of a vehicle dives when braking, and a high CoG exacerbates this. But it's been 20 years, and I've scarcely thought about the course since then!

1: https://en.wikipedia.org/wiki/Chicken_tax

Ya most of the modern systems for "ABS" do way more than just ABS; usually they're also trying to keep steering authority as well, for example. With a higher COG car, you have to be more careful of rollovers, so maybe can't help someone get a super stupid steering angle.

Checkout: https://en.wikipedia.org/wiki/Moose_test

That was true 20 years ago. The question is how much do you ease up the brake on that specific wheel, and then how much do you reapply it? You need to know the coefficient of friction of the road to know this. Modern controllers are doing a physics simulation of the entire vehicle, and part of this is the weight transfer as you go around a corner (which is partially influenced by the CoG). They then do a physics simulation of the hydraulic brake circuit so it knows how long to run the pump to build up the desired brake pressure.

Now of course this is combined with stability control (since that is required by law) and both of them are controlled by the same code.

(On a related note, I've spent way too much time reverse engineering the calibration for the ABS for a Silverado truck. Ridiculously huge program, ridiculously complicated, and I have a sneaking suspicion that the source code is a mess.)

I believe you are correct. The parent post is probably referring to traction control, or something else more recent than the original ABS.

It's actually a problem for those of us that actually use their garage for parking, as opposed to storing more junk. Most 2-car garages are around 20x20 or usable parking space or less. Even newer houses skimp on garages, because it doesn't count for square footage, and you don't really notice when it's empty.

2 modern cars, especially a mid-sized SUV or minivan, aren't going to work well with 20' of width. Even the length is problematic for clearance and being able to open the back liftgate with the garage door(s) down. A large SUV or pickup, forget it.

For a recent example, the previous gen Honda HR-V was 171” long, the new one is 180”. That brings it to about 2” shorter than last year’s 182” Honda CR-V, but the new model of that grows to 185” long. Every time a car gets redesigned it gets bigger.

Recently disappointed with the Chevy Equinox EV announcement, it takes the name of their small SUV but makes it 11” longer. Still at least impressed by the target price, but wish it were smaller.

And you’d say “Oh well they have to put the batteries somewhere,” meanwhile on the same day Jeep announced their Avenger EV. It’s a proper subcompact with 250 mile range, but it won’t come to the US because apparently no one here wants small cars.

Also waiting for more info on Mazda’s plug-in hybrid models. The CX-60 was announced for Europe, but we have to wait for a special fat version (CX-70) for the USA.

Overall disappointed with the car manufacturers lately, and with the consumer spending habits that have pushed things this way. Would greatly increased taxes on large vehicles reduce it? Maybe, but then you’re basically saying “it’s OK to kill pedestrians as long as you’re rich.”

Heh, I bought a 2004 Subaru Forester XT. Nice size, easy to park, easy to travel with dog and kid, etc. Went to buy a newer one and it was MUCH larger, felt like a boat, much taller, much longer, etc. Turns out the crosstrek (their smallest crossover) is now nearly the exact size of my Forester XT. I'd have bought one, but it was depressingly slow.

Sadly Subaru seems to have abandoned the practical small/sport SUV. The WRX wagon ... killed off. The crosstrek, nowhere close to sporty. The Forester nowhere close to small.

Well I have a 2013 Hatch. 1.4t GVM. Up a few hundred kg from the 2003 Sedan I had prior at 1.1t GVM. The vehicles I'm regularly driving with/around/near SUVs that are almost an entire ton heavier at approx 2200kg. Driven by people that have the observational skills of an ex-parrot.

Terrifying.

Even Mini Coopers are slightly larger every revision now.

Hmm. This sounds oddly similar to how phones have progressed over the years.

The average American is also growing larger with each new revision.

"Large" American people probably won't be comfortable crammed into a 90s Chevy Geo. I think such people deserve to be comfortable, is it not a basic human right / dignity?

https://cdn.carbuzz.com/gallery-images/840x560/80000/200/802...

http://data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQABAAD/2w...

Not saying it’s not a good thing, but this tries to address the symptom and not the cause. It might actually lead to drivers being even less careful since they will just blindly trust the car (as we’ve seen in many Autopilot accidents)

Even being a responsible driver you are still open to the edge case that you are going 45mph on a road that has a 45mph speed limit, doing nothing wrong, and a child steps out into your lane. Larger, heavier vehicles basically guarantee a fatality at that speed. The event was entirely out of your hands, well within the random risks of these events while driving, but your choice of vehicle has now made it a much more dangerous situation when it didn't have to be so dangerous. Pedestrians are involved in a minority of auto accidents but a majority of fatal ones, so if your goals are to decrease the risk of death in the general sense every time you go out on the road, you'd do well to choose the lightest and most sloping faced vehicle available to you.

Odds are the drunk driver is going to be driving a pick-up truck themselves [1].

This is a perfect example of prisoner's dilemma - everyone would be safer if everyone else was driving smaller cars. But because people are optimizing for their own safety everybody ends up buying large cars.

In the end, nobody is actually safer, and there are tons of negative externalities caused by everyone driving large cars (increased fuel consumption, road wear, significantly higher risks for pedestrians and other road users, etc).

[1] https://insurify.com/insights/car-models-most-duis-2020/#1.-...

You may be safe most of the time. No one is perfect. Buying increasingly large vehicles is an kinetic energy arms race.

Also a bullbar absolutely throws the vehicle off balance if you don’t put in new springs up front. Not sure if they consider that in the ratings.

Ok... a Chevy Bolt has a curb weight of 3,600 pounds as well. That's comparable in size to a Honda Fit at 163", but the Fit weighs 1,000 pounds less.

Seattle changed a bunch of speed limits to 25MPH but the problem is that the roads were designed for faster speeds so now instead of everyone predictably going similar faster speeds, you get an unpredictable mix of some people going the speed limit and some people going closer to the old speed limits.

In reality I think you need to redesign roads for lower speeds if you truly want a large percentage of drivers to follow the limits.

I agree that momentum should be the prime consideration. Especially as it relates to heavy trucks. Those guys shouldn’t be allowed to go over 55.

It'll never happen because speed limits aren't. Nobody actually follows the speed limit, people on average drive at speeds that match the safety conditions of the roads. It's not a coincidence that that speed roughly matches the speed limit. If the speed people actually drive differs from the limit and cops start actually start enforcing it the signs will eventually be set to that speed - 5 after people complain to their city council (or if they cant because fed money the cops will just be directed to not enforce it).

The only real instance where speed limits differ form "the speed drivers feel safe driving" is school zones. But outside these situations speed limits are a waste of time because the roads are designed for specific speeds and people are naturally really good at feeling that speed. They exist because cops need some objective justification for pulling over people who drive faster than the norm.

Sedans and coupes have gotten larger as SUV’s and 18 wheelers have become more and more common on the roads. They get bigger in part to fit safety features into the areas you can’t see. These cars get heavier because of government required (in the US and EU, anyways) safety systems like airbags, backup cameras and all of the wiring and other parts such systems require.

It was called boat because they didn't handle very well, and were tricky in tight situations. It was derogatory, though it was said in that tone of voice for sarcastic reasons.

Among young people there does seem to be such pressure - I hear plenty of folks around my age (late teens, early 20s) talking about a car being a boat as a downside.

Not growing up in the US and only seeing cars like that on TV, I always assumed "boat" was referring to the handling more than the size.

My Dad owned a "boat" without any shame. I don't think it was entirely derogatory. Or even if it were, that social pressure obviously wasn't very effective.

I don't recall including tractor trailers in my suggestion - the reason being that commercial drivers tend to be more safety minded, and in some cases are already routed to dedicated infrastructure.

> instance, road wear is higher for heavier vehicles, so lighter car effectively pay for the SUVs and trucks

The correct answer in that case is to quit wasting time & effort creating taxes for personal vehicles, and just make commercial truckers pay it all. It spreads the cost of the roads around to everyone who benefits (even if you don't have a car, you benefit from the roads existing). And since the damage to roads scales to the fourth power of the axle weight, the difference between a car and SUV isn't too dramatic, compared to the difference between an SUV and a big rig.

> Perhaps because this is just one of the external costs, and these costs are absorbed through taxes (for instance, road wear is higher for heavier vehicles, so lighter car effectively pay for the SUVs and trucks)

The externality we are specifically talking about is the safety risk to others that comes from having a larger vehicle. Other externalities can be solved different ways, but doe this specific one this seems like precisely the scenario addressed by liability insurance.

I remember there was a talk at Defcon that hypothesized: if you want to murder someone and get away with it, hit them with your car.

> Drivers are often not found liable for hitting pedestrians in the US even when it is clear that an error on the part of the driver caused the accident, so liability insurance is not actually capturing those externalities.

Do you have a source for this?

> However, laws automatically holding drivers liable by default for accidents with pedestrians unless there were clear extenuating circumstances, as some other countries, might be another way to change this situation so that this risk could be better captured by liability insurance.

What countries have those laws, and how have they worked out? Why not just do something sane like treating it like any other civil case where people who cause damage to others are liable for it?

> Increased liability insurance, if mandatory, is effectively just a tax collected by an independent entity.

No regulatory agency will be as effective for accurately pricing risky behavior as an insurance market.

> At least on first blush, it makes sense (to me) to just cut out that middleman and levy it directly.

The whole point of liability insurance is restitution in the case where the insured caused harm.

Adding a government tax would be adding a middleman.

One thing to note is that, not only can taxes be made progressive, liability insurance is likely regressive considering higher paying jobs are more likely to be remote.

It’s not a tax. It’s literally insurance for liability.

Yep, classic fallacy of judging actions on intentions rather than results (i.e. ignoring unintended consequences).

A. Cars get bigger because of safety standards.

B. Bigger cars cause safety issues.

C. Rather than unrolling A to adjust the original incentives, we stick a punishment (taxes) to offset some of the incentive we are placing in other areas

That’s the cool thing about insurance, it doesn’t have to be popular - you have a risk you’d like to cover, here’s what it costs you

Insurance rates should be set with actuarial data and not with political agendas. It's not insurance companies duties to set our action for societal purposes. You really do not want to give them any more power than they already have in our lives. See healthcare in the USA. That's why we have governments.

Higher liability minimums would be very regressive making support tepid among the demographics who usually want really high taxes.

This makes sense yet I never really thought about it to be honest. Here's the same things with a filter-able table version

https://www.iihs.org/ratings/driver-death-rates-by-make-and-...

Public transportation is inferior in almost every way to private cars.

The only real advantages are cost, emissions, and the ability to read a book instead of focusing on the road.

The US, being overall a very wealthy country, is going to go straight to self-driving Teslas which address the second and third consideration, and not indulge in every other irritating and suboptimal aspect of public transportation while pretending it is better.

Yes, everyone has taken the "no choice but to murder you" option past few years.

Everyone has their excuses because there's no penalty for killing someone like that.

Your coworkers are doing it do, they won't tell you they tested positive last night or this morning, frack it they are going into work, your problem, not theirs "no choice". Every hourly wage person is doing it to you, every delivery, restaurant, cashier, pharmacist, everyone. Their comfort is their priority, not yours.

When the SUV rolls over a pedestrian or cyclist, or punts a car down the road like a soccer ball, that's exactly what they are saying "Sorry, no choice".

At least the behavior is predictable now, was hidden before 2020, now obvious.

The thing is, people don't just die quick from covid. They die slow and painful. Then there is the millions who will have long-covid maybe for the rest of their lives until they kill themselves from the chronic suffering.

So many excuses, so many murderers. Society is just bizarre.

Doesn't have to be this way but it's what everyone keeps doing.

> but this paper shows that heavier vehicles are not that and in fact do more harm than good for the system overall

How did you derive that from the paper? If anything, this paper + the data from https://www.iihs.org/ratings/driver-death-rates-by-make-and-... actually sound like everyone should switch to SUVs, cause switching to SUV reduces the death rate by up to 6 times, and everyone else doing the same (according to the paper) only adds up to 50%, so the total is a reduction of up to 4x.

I mean it is kinda obvious, that the bigger - the safer. Cause in a collision of to ginormous mechs chances to keeps a small capsule with the driver intact are basically 100%.

I am impressed so many people here read the report and took it as a confirmation of their existing bias towards small cars with 0 thinking.

To the parent's point. Buses are safer for the occupants because they are heavier. But they are more dangerous to the smaller vehicles occupants.

I suppose they don't tend to go into high speed highways.

Most vehicle accidents are between vehicles. Most vehicles weigh far less than busses. And most busses spend most time travelling at lower speeds on surface streets (though long-distance road coaches are exceptions).

I've been in a bus-automobile accident, at low speed (< 25 kph). The experience from within the bus was an abrupt stop, I've experienced similar from normal braking.

The auto involved suffered major rear-end damage. The bus's front bumper was somewhat scuffed.

High-speed rollover accidents, collisions with fixed structures adjacent to a high-speed roadway, or plunging from a bridge or cliff might benefit from additional restraints. Those circumstances are seldom encountered.

Actually yes. Buses are driven by professional drivers who have to pass through a much more aggressive filter than your average SUV drive does.

When I'm out driving, walking or biking in Seattle I worry much much less about bus drivers doing something unpredictable than I do about light vehicle drivers.

one bus means 30 fewer heavy vehicles on the road

What is?

Well so far a lack of regulation has led to a tragedy of the commons like situation.