And we need more lightweight cars , not heavier, since tire wear is proportional to vehicle weight to the fourth power. Ironically, CAFE regulations and EV incentives both did the opposite
I'm not sure why you're being down voted for suggesting a practical and fact based solution. The USA is, regrettably, not making a pivot towards public transportation anytime in the near future. So, lighter cars are one way to address this issue.
You didn't expound upon your point about the unintended consequences of CAFE standards but they're very real. Instead of making smaller and more efficient sedans per the guidelines, car makers opted start making all of their vehicles "light trucks" -- 80%+ of new vehicles are SUVs or bubbly looking "crossovers" -- which are not subject to the same demanding standards. Small sedans also cost less and would require ongoing R&D to continue to meet the CAFE standards. The end result, as this thread is interested, is heavier vehicles with bigger tires and more plastic in the environment and our brains.
Los Angeles is one of few US cities that is managing to build at least some new transit lines. Increasing density in desirable cities is actually pretty easy, all you have to is make it legal (by-right zoning) and then the market will do the immensely productive and profitable thing.
I find it interesting that at a certain time in Los Angeles, a segment of society could afford a craftsman cottage house, but not afford an automobile. This was the prime era of the Pacific Electric streetcar suburb, say around 1890-1920. Today, obviously, anyone who can afford a house anywhere in the country can afford an automobile.
The end of the Pacific Electric system was not a conspiracy theory by tire companies or anything like that; the price of the cars dropped and that's what consumers preferred, i.m.o.
From an infrastructure perspective building out instead of up is incredibly expensive. Not just transport but also water, sewage, electricity and internet.
I should specify: it's more expensive for the developers and their home-buying customers to build up instead of out.
All of that stuff you listed comes from tax dollars, and people ultimately care less about that than what's coming out of their pockets for a home purchase. Well, until it's unsustainable, anyways.
Yes exactly. Building is cheap in the US relatively speaking. There are tons of grants and government money to help move things along. Those avenues don't really exist for maintaining things that were built with grants and outside funds. So we see TONS of expansion followed up with almost no maintenance and suburbs and less populated places literally cannot afford to maintain the services that they utilize. The burden is almost entirely shifted onto renters in urban areas instead.
In this country we have this ideal of a rugged individualist whose out there living off the land and making his own way. Never will this rugged individualist acknowledge that he's dependent on 10x as many miles of roads as his urban counterpart. Never will this rugged individualist acknowledge that providing him with internet access on the state's dollar costs orders of magnitude more than someone living in a sustainable location. Same with delivery costs and literally every other thing this person consumes. They get to pretend to be a self-reliant individualist while leaching off of the tax dollars of urban residents who cost a fraction of the amount to support.
> Never will this rugged individualist acknowledge that providing him with internet access on the state's dollar costs orders of magnitude more than someone living in a sustainable location
Thankfully we have Starlink to replace pork consumption with actual services.
Yeah, I’d expect EVs to get lighter over time as technology progresses. Car bloat is a much bigger problem. Totally insane that little practical city cars like the Honda Fit have gone practically extinct in the US in favor of bigger, heavier cars that don’t even necessarily bring improved cargo capacity for all that extra bulk.
I have a 2018 Fit and it's a fantastic car. It gets 36 MPG and has much more interior space than it would seem. I've had taller people ride in it comfortably and its crowning achievement was fitting a hot water heater in the cargo area with the rear seat split -- without having to remove the child car seat on the other side. Pair a roof rack and you really don't need more -- especially day-to-day.
It's a crying shame that they've stopped selling them in the US. Marketing (the real men need their Rams, thank you very much!) and the CAFE loophole seem to have won the day, though, and we're all worse off for it.
Marketing does seem to work, especially over generations. I think the main reason trucks/SUVs were marketed so much was because of a 25% tax on imported light trucks and not cars. The so called "chicken tax"[1] was imposed on light trucks in 1964 and is still with us today.
A big reason car companies push trucks so much is that they are more profitable per unit. Demand is extremely limited in terms of quantity, because you can only really sell about 1-2 cars per family, per about 10 years.
That means, all else being equal, a car company makes more profit selling a vehicle that has a higher profit margin. The $80k trucks my family members buy do not cost 3X as much to manufacture as say, a nice Camry, but the price you pay is about 3X. This means the dealer/manufacturer just outright make more money if a higher percentage of people buy trucks instead of small cars.
Consumers have "signaled" that they will be fine paying three times as much for the same exact feature set (no, they are not hauling anything, and there certainly isn't a massively higher percentage of Americans doing truck things than 50 years ago), even using longer term loans to make it happen.
When the car market has been basically saturated for decades, how else do you "make line go up" than selling the same product (transportation) for more money?
> The $80k trucks my family members buy do not cost 3X as much to manufacture as say, a nice Camry, but the price you pay is about 3X.
> ... even using longer term loans to make it happen.
I don't understand how so many people are driving these vehicles. Not only are they 2-3x as expensive to buy or lease but they're also 2-3x more expensive to fuel and maintain. (Probably to insure, too?) I don't have any data to back this up but my intuition tells me that these vehicles and their loans could be the cause of the next subprime mortgage-esque financial crisis.
It really is difficult to imagine a better vehicle for suburb/city usage than the Fit, unless you have a bunch of kids/people to move in which case I’d skip crossovers/SUVs entirely and go straight to minivans (which are also better than SUVs for most peoples’ needs).
Roads and road standards are a tragedy of the commons. People keep buying bigger cars and demanding more, wider lanes and parking spaces because they don't take any of the burden individually - it's the taxpayers as a whole that foot the bill.
Paradoxically most of the 'small government' types are often the biggest road users.
The solution to tragedies of the commons is to internalize externalities. Tax should scale with carbon use, congestion contribution, and microplastic emission.
> tire wear is proportional to vehicle weight to the fourth power.
Does this mean that a bus that weighs 10 times as much as a small car will produce 10000 times as much tire dust? If it does, I'm not sure if investing in buses will reduce tire dust at all. A bus can replace a lot of cars, but 10000 is a stretch. We need more trains.
I think the root observation here comes from https://en.wikipedia.org/wiki/Fourth_power_law which really talks about the inferred stress to the road for given weight on the axle, not tire wear based on vehicle weight. The above seems to be using a simplification based on passenger cars staying with 4 tires across 2 axles but how this relates to tire wear is going to be a bit more complicated when you start talking about vehicles which can have more axles, more tires per axle, and significantly larger tires.
I'd believe buses have a lot of tire wear compared to an individual car but I wouldn't use that relation as proof of just how many times so.
trams were popular in tons of places before, I understand they improved traffic significantly compared even to today, and they'd still have a positive effect now, I think. But most places shifted towards a car centric focus and we lost those.
Do you have a citation for the vehicle weight to the fourth figure? There is about a 2X variation in the weight of the vehicles I’ve owned, but even accounting for differences in tire size, I can’t come up with a 16x difference in how often I change the tires.
Thinking about it a different way, there isn’t much difference in recommended tire pressure among the autos I’ve owned. That means that the pressure between the road and the tire is relatively constant but the surface area of contact is directly proportional to vehicle weight. For a fixed contact pressure, I am struggling to imagine a physical process by which the rubber loss is not proportional to the contact area.
The fourth power law is usually applied to deformation of asphalt roadways (here's a citation for that: https://www.researchgate.net/profile/Maxwell-Lay/publication...); I haven't heard it applied to tires before. If I had to guess I'd agree with you - I would expect a smaller exponent, particularly if the tires are designed for the given load.
This Engineering Explained video seems pretty thorough. The short of it is that your intuition is in the right direction, its definitely not to the fourth power of weight. Vehicle weight does contribute to wear but according to Continental its less important than driving style and road curviness.
Most studies I've seen on this topic agree that the amount of pollution created is not linear, and this also makes intuitive sense. The heavier your vehicle, the wider and/or larger diameter your tires need to be to give it the required amount of grip. If those bigger tires wear out in the same time as your smaller vehicle tires, you've already created considerably more pollution.
I know this figure comes from road wear. I don't know if it applies to tire wear, and indeed I suspect it doesn't, if only because tires tend to scale with vehicle weight as you mentioned. I think road wear may be associated with structural cracking of the road which may not change significantly with tire area.
Tire wear is caused by the surface of the tire being rubbed off through contact with the road. Most tire replacements happen because too much rubber has worn off of the contact surface.
While that happens some in the other direction, that’s not what usually causes road failure. You can tell this because pot-holes and other road failures have abrupt edges - they are not the road material until nothing is left but the earth beneath.
Roads also wear by being elastically deformed by the weight of the vehicles upon them. Eventually this deformation leads to failure of the road material, and it breaks away from the rest of the road, creating cracks and pot holes and so on.
Because the cause of failure is different, I don’t have any reason to expect the effect of vehicle weight to be the same. Moreover, unlike tire wear, its easy to hypothesize a physical reason that heavier vehicles will disproportionately wear the road: heavier vehicles will cause more deflection, and every material I have experience with will fail from repeated deflection faster if it’s deflected more.
Also motorcycles/scooters. Unless you have children or live in a place with serious snow a motorcycle and a car sharing app/rentals for when you need to haul a sofa or something is a great combo.
Cheap, easy maintenance, good fuel economy and speed, traffic jam immunity..
None of these things are going to happen. Voters keep voting with their votes and their wallets that they want bigger cars and don't care about climate change. Meanwhile reactionary billionaires have hijacked most of our mass media as we blow by the 1.5°C Paris agreement and Trump dismantles our science institutions.
EV/hybrid only "zones" in Europe are crazy to me because the electric cars leech more tire carbon into the air anyway. Some regulation seems intelligent on the surface, but the devil is in the details.
Solid/particulate pollution from tires is definitely a problem, but in terms of carbon specifically isn't it many orders of magnitude less than the carbon from gas engines or electric power plants?
> These particles can include synthetic rubber, plastics, carbon black, and trace metals (like zinc)
you're correct. I mistakenly thought it was only carbon coming off the tires. So yeah, EVs have a significantly lower carbon output that ICE vehicles. My point still stands but thanks for the callout.
EV/hybrids also have regenerative brakes so emit less brake dust. Between emissions, tires, and brakes I'd be curious to see how it balances out.
But really cycling and transit are the way to go to make cities more liveable. Personal cars take too much space in a city and ruin the built environment for everyone not in one.
These zones are generally densely populated areas, and in Europe they usually have low speed limits, and roads design to encourage driving at low speeds.
To think that the minuscule difference in tire dust is significant at all, compared to the pollutants that EVs completely eliminates, is absolutely ridiculous.
The devil is in the details, yes. Have you considered that the policy makers have actually looked into the details? Have you looked into the details? Have you read any detailed reports about tire wear or did you just make up a problem based on your own intuition? Because I’ve seen reports from EV fleet operators that indicate that they see no difference in tire wear. Most likely the added weight (which isn’t all that much for modern, smaller EVs.. you know, the ones that people actually drive in urban/suburban areas in Europe) as a factor is drowned by other larger factors.
And we’re not that far away from EVs with the same or lower weight than their ICE counterparts, so getting these kinds of policies in place has some forward-looking aspects to them as well.
Excessive NO2 emissions spewed by diesel engines not meeting regulations very literally removed years from our collective life spans in city centres across the world.
Despite their own health hazards no amount of tire particulate from EV's can achieve that level of widespread public health impact.
