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Comment by SilasX | Hacker News Reader

That's misleading -- yes, in the aggregate, gas taxes cover only part of the expenses, but that's not because of personal cars. Damage on the roads -- and thus maintenance costs -- scales with the 4th power of weight per axle. So the damage is virtually all from large trucks, with sedans and SUVs as a rounding error.

If you were to apportion out the maintenance cost due to personal cars, they are overpaying.

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For those wondering about the source of the "4th power of weight per axle", I found this after some short, but intense, Googling:

http://co-asphalt.com/wp-content/uploads/2015/03/TrashTruckD...

Reference 1 lead me to this: (Page I-11) https://habib00ugm.files.wordpress.com/2010/05/aashto1993.pd...

From that: "The load equivalency factor increases approximately as a function of the ratio of any given axle load to the standard 18 kip single axle load raised to the fourth power."

That is also cited here, on page 14: https://wisconsindot.gov/Documents/dmv/agri-eq-veh/ag-study/...

I am bad at math... could you help me understand. A 80,000 truck and 5,000 car drive down the road... how much more damage does the 80,000 truck do? Thank you.

If the 80k truck has 5 axles (as is typical of an 18 wheeler) and a 5k car has two, then the truck has 16k on each axle and the car has 2.5k on each axle.

Because the damage scales with the 4th power, then the damage ratio is the 4th power of the axle weight ratio:

(16k/2.5k) ^ 4 = 1677x as much damage.

Edit: Sorry, that oversimplifies it a bit. For the same vehicle, the damage scales that way, but for a fair comparison, you'd have to account for the fact that the weight is distributed over more and bigger tires on each axle. Still, that should show you how the math works.

So the damage is virtually all from large trucks, with sedans and SUVs as a rounding error.

Which is why the California tax on gasoline is 48.7¢/gallon and the California tax on diesel fuel is 67¢/gallon.[1]

Federal tax on gasoline is 18.4¢/gallon, and diesel fuel is 24.4¢/gallon.[2]

I'm not defending the trucking industry. I think more stuff should go by train instead. But truck fuel is taxed more heavily than car fuel. (For those of you in other countries, the number of cars running on diesel in the United States is about 3%.)

[1] http://www.cdtfa.ca.gov/formspubs/l561.pdf

[2] https://en.wikipedia.org/wiki/Fuel_taxes_in_the_United_State...

It’s taxed slightly more heavily. But trucks cause literally thousands of times more damage than cars.

They also require more gas per mile. It seems like it should roughly add up to paying a few more times than cars (they're a few times less fuel efficient).

Yes, the average car in the US gets about 25MPG, while the average tractor trailer is 6MPG, so about 4x the fuel per mile. Accounting for the higher tax rate, they’re paying maybe 5x the tax per mile, while causing maybe 5,000x the damage.

You could tax trucks like 1000 times more. But don't expect the butter and milk to stay the same price.

Butter and milk that don't have to travel as far by road would be cheaper. So much of our national Walmartification is possible because of roads are subsidized.

No, it would not be cheaper. It is not cheaper today and making food today is profitable (and possible) only thanks to economy of scale. Automation on this level is not here yet.

> don't have to travel as far by road

It doesn't have to. It can (and it does because it's better).

The point may be that they should not be this price to begin with.

Externalities that aren't properly accounted for (and paid for) end up causing inefficiency.

The milk would cost more, but we'd save even more money on road maintenance.

Then many trucks could be adjusted to have more axles and lighter loads, saving money on both ends.

The end result is a better system.

Maybe eventually the cost will go down for milk because we chosen more efficient ways of transporting milk?

Is this some kind of joke? If the taxes already cover 25% of the expenses then adding 1000x on top means you would tax 249 times more than you need. To make it fair you first have to give truck fuel an adequate tax (so it covers 100%) and then divide this tax by 1000 for light vehicles.

If you think it's a joke you're taking the words far too literally.

"like 1000 times more" is not a full proposal. Yes you would reduce car taxes appropriately. Yes you would figure out the actual amount to balance the budget.

> The milk would cost more, but we'd save even more money on road maintenance.

This would adversely affect the poor as they drive less and still need milk.

There are much better ways to help the poor than by subsidizing trucking.

My point is you can't just look at something and not take into account where else it may impact.

Also, we need to get much better at helping the poor.

My point is that “it will hurt the poor” is a very old and very tired response to proposals that externalities should be accounted for in the cost of goods.

Part of getting better at helping the poor is helping them directly rather than using extremely inefficient and indirect subsidies on various industries to do so.

literally anything that has any negative effect will affect the poor more because the rich have more resources to mitigate the negative effects.

so unless you have a solution with no drawbacks, there's nothing you can do to not 'affect the poors'

The reduction in sales taxes would more than make up for it.

We’re paying for it either way. I’d rather the payment be apportioned by the extent to which you use products that have to be transported that way; it gets the incentives right.

And you do get a better MPG with Diesel so it should to be fair be taxed more.

Those taxes should be proportional to the wear, otherwise it remains unbalanced.

If we are talking about maintenance costs, sure trucks should pay their share, but congestion (the reason to build additional roads) is caused primarily by passenger cars.

Congestion doesn't drive maintenance costs. It may drive infrastructure needs but that is an entirely different problem, and one which taxing conpanies such as Uber and Lyft actually help to lower.

What is more expensive, train or road maintenance? What gets better total utilization rates?

Road gets you everywhere, rail only gets you to the nearest terminal. Depending on the signalling system used rail can have a higher capacity from terminal to terminal, leaving the 'last mile' (which in reality is more likely to be the last 100 miles) to be travelled by road. Road needs more maintenance and the work itself is more labour-intensive.

Imagine a package-switching network comprising an (electrified) rail backbone with roads spreading from terminal nodes to the destination points, fully automated package store-and-forward, electric self-driving trucks.

This would cost loads of money and loads of jobs. It might also solve parts of the problem. Maybe Amazon's successor is already thinking of something like this?

> Road gets you everywhere, rail only gets you to the nearest terminal.

That is not true. Road gets you to where the road serves, just like rail. With a good enough coverage, virtually all transportation needs are met.

Exactly this. Of course, if they tax per axle and tonnage combination, it’ll just be passed on to consumers anyhow as most of trucks are distributing goods which directly or indirectly end up in the hands of consumers. However, it would be quite fair to do, I think.

Sure, but it might also have some other nice side-benefits, like favouring railroad expansion. Having transport by lorry being artificially cheaper is non-ideal for lots of reasons.

In the short term it would get passed on to consumers. In the medium term supply chains would figure out how to reduce shipping by road. In the longer term (in conjunction with other changes) we might be able to get larger-scale urban development on a more sustainable track.

If we could properly price externalities (not just road wear but also ground water contamination, CO2 emissions etc.) there are many parts of our economy which could be made dramatically more efficient and less harmful without that much overall change to human quality of life.

This would devastate the economy.

For example: Exxon mobil profits in 2017 were 19.7 billion. Fukushima cleanup costs exceed 180 billion.

There is no way to do what you are proposing without massive price increases in electricity, gasoline and virtually every other good. I wouldn't be surprised if when you priced all of this in you discovered that people couldn't really afford electricity anymore.

Also this economy would never be able to have exports because the price of producing goods would just be insane.

The truth is we can't afford the externalities without an economic implosion that would realistically end with an extreme political group taking control in the ensuing chaos and undoing everything you are proposing.

> For example: Exxon mobil profits in 2017 were 19.7 billion. Fukushima cleanup costs exceed 180 billion.

So you could cleanup one of the worst "spills" in history with a mere 10 years of a single company's profits?

That sounds perfectly OK.

Even better, it would have been possible to avoid that spill with that money and you'd probably have enough left over for a healthy profit afterwards.

Mitigating climate change is essentially going to cost all of the direct profit ever made by all the companies in the fossil fuel discovery, extraction, refining, and retailing businesses.

Think 85 trillion USD, real value. That's about 1/3rd of the total current wealth of the entire world, by my back of the envelope calculations.

The thing about externalities is: somebody pays, it's just not the person who caused them. Redirecting that cost back to the source would be a good thing. There would then be incentives to do the most efficient thing instead of the most wasteful thing. This would actually make everybody richer.

How much of our wealth is being wasted this way? I'm guessing that it's a lot.

Actually, of trucks were taxed on a ton/axle basis instead of ton+axle basis, the net road wear would be dramatically reduced. Think 6-axle, tripple-tire trailers.

It's not that simple. HN readers could absorb the increase, but the poor can't.

That's not really the view from a city budget. Cities don't have that many truck routes and their costs are dominated by maintaining streets where virtually all the traffic is light vehicles. For the state it is a bigger problem because almost all state route are truck routes.

Even then, the same phenomenon means that the dominant source of damage to those streets is the delivery vehicles; smaller cars still cause a disproportionately small fraction of the damage and are overpaying via taxes. Ubers are not externalizing here.

Without much better data the best you can say is that Ubers are benefitting from externalities at a rate lower than other, heavier vehicles. It's still likely they aren't paying their fair share.

A vehicle twice as heavy per axle is doing 16x the damage. Unless the taxes on delivery vehicles scale like that, a sedan is subsidizing the costs.

A road that's never driven on suffers damage from the elements, and the passage of time.

A truck does more damage then a car? Great. But there's an upfront road maintenance (not to mention construction) cost that you have to pay, regardless of who uses the road. Gas taxes do not come close to capturing that.

How does this account for all the upkeep on the residential roads where a large truck almost never travels. Sure, large trucks may account for the vast majority of wear on roads where they travel, but I imagine the majority of the roads in a city rarely see large trucks, and still need regular upkeep.

Without some sources to back up your claims, I'm not sure if it's accounting for that or not. Can you supply your sources so we can look into exactly what that statistic means?

Are you sure about that? I see garbage trucks, delivery trucks (package, furniture, appliance etc.), lawn service trucks, salt trucks, snow plowing trucks etc day-in, day-out.[1] And to do their job, they probably need traverse 95% of the paved roadways on a regular basis. Granted, you don't typically see 18-wheelers tooling around most neighborhoods[2] but there is quite a bit of truck traffic through even moderately populated urban and suburban areas every day.

[1] If your argument is that these are all 'light' vehicles, my city disagrees with you. They recently cited road damage from the variety of garbage hauling services as a reason to limit our options. Not that I entirely buy that as the only or even main reason they did so... local politics and all that.

[2] However they have been known to use secondary streets when they shouldn't.

We're talking about California. There are no major cities in California in possession of snow plows and salt trucks. A garbage truck goes down the street once per week, yes. The overwhelming majority of traffic on most city streets is cars and light trucks. The main cause of damage to most city streets is the mere passage of time, and rain.

We are talking about California. What rain? :-P

Thankfully CA is now finally pretty well drought free, after getting pretty decent rain the past couple months. https://www.sacbee.com/latest-news/article226462260.html

Drought map https://droughtmonitor.unl.edu/CurrentMap/StateDroughtMonito...

Reservoirs are doing well http://cdec.water.ca.gov/reportapp/javareports?name=rescond....

Of course, this is an El Niño year, so we’ll see whether we return to severe drought in the coming years.

The salt and plowing trucks are part of the maintenance of the road needed for the cars. You defeat your own point here.

Not at all. I was making the point that there are lots of trucks on most roads all the time, not that they aren't necessary.

Also, while salt makes the road drive-able in the winter, it actually does long term damage to the road (increases the number of freeze/thaw cycles.) Similar with plows: they increase the rate at which the road surface deteriorates. While they both are necessary to keep roads operable for vehicles in the winter, they are the opposite of maintenance longer term as far as the road surface is concerned.

This is why the Netherlands also has weight-based vehicle taxes (on top of the gas tax and many other taxes).

As do the states. Commercial trucks pay a lot more road use tax than passenger cars. Whether it's proportional to the damage they cause I don't know.

There are counter examples like the federal and some state (e.g. California) tax breaks for trucks over 6,000 pounds, providing relief to all of those orthodontists who needed a Hummer to get to the office.

I'm waiting for people to buy the actual military surplus Hummers for all those Whole Foods that are on top of mountains.

Damage isn't the only thing involved in people using the roads. Roads are a public good (in contrast to railroad tracks which are a private good).

The state effectively charges for the use of roads both to pay for maintenance and to make sure that the road remain usable to a reasonable cross-section of people. This is just as landlords charge for the use of land even when that land isn't consumed.

Here in northern Sweden we have a lot of wear on the roads. After a few years you can clearly see where most drive because there is a deep depression after the wheels. If you drive a truck in the track you will notice that you don't fit, the distance is slightly smaller than the trucks wheel distance. It does however fit exactly for the cars.

We do however all have spikes on the cars in winter, I'm guessting this helps a lot. The trucks usually does not have spikes. There is a lot of trucks too, hauling wood out of the forests.

Worth noting that the damage to the air, increase in noise pollution, and increased costs of health care spending from injuries, lung disease, etc. from both is substantial.

The more technical term for this is "fatigue damage". I read years ago that the fatigue damage inflicted by a truck loaded to the legal weight limit (and it's often exceeded) is 9,000 times that of a car.

The damage done by cars is usually from snow tires.

And add to that pollution caused by large trucks. Some are literally hard to follow behind due to the cloud of poison they are fuming all over.

California's crusade on sedans to cut down on pollution is a joke.

You are joking right? Just because the pollution from cars is not visible, doesn't mean it doesn't exist. And there are a 1000x more cars than trucks.

No need to use the 1000x number, there's actually information about this out there, at least when it comes to greenhouse gasses. In 2016:

https://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=P100USI5.pdf

Medium and Heavy duty trucks: 425 Tg CO2

Light-Duty Vehicles (passenger cars + SUVs, pickup trucks, etc): 1,106 Tg CO2

Are there studies for how these measure up in practice? Also curious about wear per weight characteristics between concrete and asphalt.

Damage on the roads -- and thus maintenance costs -- scales with the 4th power of weight per axle.

[citation needed]

Except there are a 1000 times more cars on the road than trucks, and we actually need trucks. We don't need cars, at all.

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