UK electric car drivers should be charged per mile, say campaigners | Hacker News Reader

UK electric car drivers should be charged per mile, say campaigners

theguardian.com

14 pointsPaulHoule67 comments

By the same logic, all gas cars should be taxed on a sliding scale, where the more fuel-efficient cars are taxed at a higher rate. It's important to society that we incentivise people to drive the most polluting and climate-destroying vehicles.

More fuel efficient gas cars tend to be lighter, and pavement damage scales as the fourth power (!) of axle weight.[1] It's likely that fuel-efficient cars—despite paying less in road taxes—are still overpaying for the road damage they cause.

Of course fuel-efficient cars will still have similar impacts on road congestion and parking. So the real question is: what percentage of the fuel tax goes to paying for road damage, and what fraction goes to compensation for other externalized costs: urban congestion, parking, smog, noise, collision risk, pedestrian stress levels, etc?

[1] https://en.wikipedia.org/wiki/Fourth_power_law

All cars should be taxed on a formula of miles and weight. I own an EV, and I'm happy to pay my share, especially for the increased weight due to the battery. I'd love to see taxes that incentivize smaller, lighter cars in general.

And even if the power is green, less use is always better. Less tire wear and in general less energy used which means it can be used for other things or in general produced less.

I'd never heard of that fourth-power-law, fascinating. In fact I can't think of any other relationship in 'nature' scaling with the fourth power, and it seems that that is indeed rare, given the fact that the Wikipedia article is literally called 'fourth power law' and only refers to this effect. (Though I sure would have liked more background info on the actual physics involved; it seems they basically just observed cars and trucks driving on roads, measured the damage to the road, and called it a Law.)

Flow through a pipe scales as the fourth power of the radius

https://sino-inst.com/pipe-flow-vs-pressure-relationship-cal...

This came to my attention when I was teaching Physics 102 at Cornell which was an auto tutorial course for pre-meds that had an unusual focus on fluid mechanics for an intro physics course.

It's more a rule of thumb than anything approaching a law. The exponent varies based on a number of factors like existing road condition, road construction standards, speed, weather conditions, etc.

Doesn't the cost of heating a dwelling involve a fourth power of the difference in temperature, outside/inside ?

Thermal radiation is the other classic

I too immediately thought of https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law .

There's also radar reflection, "Observe that the received power drops with the fourth power of the range, so radar systems must cope with very large dynamic ranges in the receive signal processing." - https://www.eetimes.com/radar-basics-part-1/

I would also call it a classic as I learned it from this scene in Robert Heinlein's book "Rolling Stones": "The result was eight shiny right-angled corners facing among them in all possible directions —a radar reflector. ... The final result was to step up the effectiveness of radar from an inverse fourth-power law to an inverse square law — in theory, at least. In practice it would be somewhat less than perfectly efficient ...", https://archive.org/details/rollingstones0000robe_q7v9/page/...

A quick search on Google Scholar finds there's a fourth-power law for shock waves:

"A fourth-power law relating the stress jump through a steady structured shock wave and the maximum strain rate within the shock wave has received recognition as a unifying relation over a sensibly wide range of materials and shock compression amplitudes." - https://pubs.aip.org/aip/jap/article-abstract/107/1/013506/2...

"Observations on the fourth-power scaling of high-pressure shock waves in solids" at https://pubs.aip.org/aip/jap/article-abstract/130/24/245901/...

and one with irradiance, though at the forth-power of the cosine:

"The cosine-fourth-power law states that the irradiance at any point in the image formed by a photographic lens, in the absence of vignetting, is equal to E_0 cos^4 β" - https://nvlpubs.nist.gov/nistpubs/jres/39/jresv39n3p213_A1b....

I also found the following at https://pubs.aip.org/aip/jap/article-abstract/75/6/3075/4001... :

"The third‐order nonlinear optical susceptibility χ(3) of this glass was found to be proportional to the fourth power of the radius of the colloid particles or the fourth power of the absorption coefficient at the peak of a plasmon band when the total volume of the colloid particles was constant."

Well, the most fuel efficient cars will often be hybrids, whose extra components (battery, 1-2 motors) will offset any savings that you'd see in a pure ICE powered vehicle.

The point was addressed at the end of the article: The charge would be for all vehicles, with EVs and low-emission vehicles having the lowest rates. So the headline was clickbait.

(That would be the theory at least. How well such a proposal would survive the lobbying onslaught from pro-combustion groups is another question...)

Actually, it is important that a tax for road care stays a tax for road care so it would be better to replace it with a charge per km adjusted by weight of the vehicle (the primary contributor to differential road damage per km, atleast that we can reasonably and unobtrusively measuee)and adjusted to net out fuel taxes already paid for road maintenance. Could be collected once a year at registration renewal.

The annual fee becomes hard for those living paycheck to paycheck, they would get a large bill. Maybe something akin to payroll, where you pay in regularly and then rebalance to zero once a year

that argument doesnt really hold any water in amy context it is used. If you are capable of paying as a gas tax eaxh trip to the pump, but not as a yearly lump sum you probably shouldnt have a car, let alone an electric car.

There are a lot of people that are really bad with money. Also when you don't have a lot of money you pay what is in front of you. I think this the person above is correct, something like a prepayment with adjustment at the end is probably a better solution.

Facilitating people who are bad eith money feels like another way to let people be shitty, which should not be accomodated. There is an argument forprepayment if it in reases likelihood of collection but at least put a penalty additional fee on it to limit the fa ilitation of people beong shitty.

this attitude is how the haves keep most the have nots from ever escaping poverty

could you try compassion for your fellow humans instead?

I am showing compassion. Allowing people to be shitty is not compassion, it is future problems for everyone. Compassion is letting them know this is not ok

ICE is taxed at the pump, and has these efficiencies built in.

EVs are charged at home, so it is hard to tax per refill. Certainly within EVs there ought to be differences based on weight and wear on the roads. However, they are bypassing paying for their shared good of common roadways. With the migration away from fossil fuels, we will have to find a new way to pay for road repairs

> 65% of the public believe it is fair for electric car drivers to be taxed, but at a lower rate than petrol and diesel drivers

Electric cars still use roads, which still need to be maintained. There's no "extrapolation of logic" required, because the tax on the most fuel efficient cars already dwarfs that which would be paid by electric cars.

Electric cars also weigh more and brake more than cars of equal weight. Petrol is already taxed ostensibly to pay for roads. So if anything, EVs just need to be taxed and everything else can be left alone.

This already happens for cars in the UK with 13 different road tax rates based on g/km co2 emissions. https://www.gov.uk/vehicle-tax-rate-tables . My last petrol car paid £0 road tax.

If the tax is intended to offset the wear and tear on roads, the fairest way is pay-per-mile.

But now that EVs are a viable alternative the gas tax should still exist to offset the externalities involved.

Per mile or per mile times weight to the fourth.

They are already taxed by efficiency+use in a very obvious and direct way: through fuel taxes. Electric cars on the other hand are not subject to fuel taxes.

Petrol tax directly incentives fuel efficiency

While my initial reaction was negative, after thinking through it a little it does seem reasonable to look into a replacement for the fuel levy as a road usage tax now that the number of ICE cars keeps falling.

EVs don't have any less impact on road deterioration and maintenance needs. If anything they cause more damage as a result of their higher average mass and acceleration.

Whether a per-mile/km tax is the right approach or even feasible is another question, but I don't think it's entirely wrong to be considering some sort of road usage tax for EVs that's proportional to the fuel levy.

If you're doing this to offset damage done to the roads, something to keep in mind is that passenger cars are totally irrelevant in terms of road damage compared to large trucks, because road damage is a function of the fourth power of axle weight ( https://en.wikipedia.org/wiki/Fourth_power_law ).

That may be true, but heavy goods vehicles are already taxed in the UK according to a sliding scale of their mass and number of axles in order to account for their damage to roads. [0]

[0] https://assets.publishing.service.gov.uk/media/64ca1f035c2e6...

Yes, but I think OPs point is if you're taxing vehicles according to their contribution to road damage, then cars should efficiently be taxed at 0 (I don't know I'd that is true, but it seems to be the point their making). If heavy goods are 100% of the damage, they should cover 100% of the tax.

Now that said, I'm not convinced they are actually 100% of the damage. I've seen many residential streets in need of repair that essentially never see heavy vehicle traffic. And I'm also not certain that taxes should be based on cost added vs value provided - but it's a reasonable discussion to have.

But again this seems short sighted. Electric vehicles (vs ICE) remove a ton of negative externalities from society. And while they do bring others (in how many of their materials are sourced) they are a big net positive. Don't disincentivise them because of a change in fuel tax revenue.

> I've seen many residential streets in need of repair that essentially never see heavy vehicle traffic

Maybe just the freeze-thaw cycle?

Yeah, weather/time do a lot, it's definitely not all trucks. And a lot of them are maintained just so they're available for everyone, whether they're being heavily used or not. So I don't actually think that trucks should bear everything. But I do think they should pay a large fraction of highway maintenance budgets, partly so that they're not unfairly advantaged versus cargo rail.

Mostly putting it out there so that people don't start thinking that EVs need to be taxed more highly than ICE cars because they're a bit heavier.

Nice. Those amounts seem kind of low, though? Not sure if I'm reading it correctly. A truck that weighs 20x the amount of a passenger car, with 2 axles, appears to pay 300 pounds per year?

Also, weirdly, a 40,000 kg truck with 2 axles seems to be taxed less than the same truck with 4 or more axles.

These are annual registration taxes, not usage taxes.

Ideally you'd want a sort of usage tax also based on this, but implementation has been difficult to achieve. [0]

[0] https://www.lafabriquedelacite.com/en/solutions/weight-tax-a...

Yeah, a fixed tax, but based on weight, which is sort of a low-resolution usage tax.

300 pounds is more, but not very significantly more, than car registration in many US states.

Perhaps more points of contact is better for the road?

Yeah, it should be, but it seems they're taxing more axles more for the same weight, so it seems like something else is going on there.

That fourth-power is more complicated then your summary suggests.

For example, it's also a function of road design, which is why a high-speed limited access road is able to handle significantly higher loads than a suburban cul-de-sac.

Consider that a bus weighs a lot more than a car, so a simple 4th power analysis suggests it will cause several orders of more damage than if everyone drove their own car.

However, busses tend to run on bigger roads which are better designed to handle the weight (with the expectation that people will walk a few blocks to get to the stop), rather than residential streets which are mostly designed for private vehicles and the occasional delivery truck/van.

On those roads, heavy passenger cars are relevant to road damage.

Ah, good point, thanks!

Zero taxes are a good incentive for drivers to switch to EVs, so if the goal is to get people to switch, it might be a better idea to wait. Call it a subsidy.

UK is planning to ban sales of ICE cars in 2030... So it does make sense to start implementing the system now to be ready then. 5 years is short time for this type of system.

Worth noting that hybrids (which are basically still ICEs) will be allowed until 2035.

we could also just accept the fact that the roads are a public good, and not spend the extra money to try to weigh exactly who is causing the most wear and bill them separately. if I live in an urban center and bike everywhere, all my goods are still arriving by road. I hope that they're there when I need to be trucked by ambulance.

"and not spend the extra money to try to weigh exactly who is causing the most wear and bill them separately."

To the contrary - that's a good reason to subsidize the construction of of infrastructure, but having some sort of incentive to use less damaging forms where possible makes all kind of sense. Part of the reason for the stupid-sizing of consumer vehicles in the US over the last decades is because the incentives are all messed up.

You need to somehow pay for the roads. And it is never small sum. Per mile tax seems most reasonable. It can also be set on vehicle mass. Though likely cargo does need some subsidising as entire existence of modern society depends on it.

Pay per mile on public roads is the most fair, with the multiplier based on the wear and tear the car causes to the road.

I would never trust any sort of gps system to not be used against me however.

I would envision such a system to be based purely on odometer reading since that might be easiest from a logistics perspective

One idea that comes to mind that would be relatively simple sanity check is data from average speed cameras that UK has. Somewhat dystopian solution would actually be also track distance driven between these. And add it together over the measuring period.

that would be good, but UK politicians are very interested in pricing usage based on time of day

which doesn't work if you only check the odometer once/year

Wear and tear scales with the fourth power of the weight on an axle. So this does provide a strong incentive for lighter vehicles, it also becomes a drag on moving things in the economy which is not so desirable, and essentially becomes a kind of consumption tax, which is perhaps a bit more progressive than fuel duty though I’m not sure.

A shame that they're not talking about the weight of the vehicles. It's not fair that a 3 ton twatmobile pays the same as a Honda Jazz. They use the road more, make it worse for everyone else, make them pay more.

Pay per mile schemes are fairer than fixed higher annual taxes on electric vehicles, since those often over-tax low mileage vehicles and under-tax high mileage ones.

The biggest problem with them, by far, is how do you collect this mile information? The current popular option is to plug in a OBD-II dongle that constantly drains the 12-volt battery, and sends your location data to some third party who then forwards it to government (with questionable privacy assurances).

You could also just use odometer, but rolling back would become commonplace if you'd pay less.

> The biggest problem with them, by far, is how do you collect this mile information?

In the UK every car is required to have an MOT done, which is an annual, comprehensive, safety check of the vehicle. The results are recorded with the Ministry of Transport. It would likely be very trivial to add odometer reading to the recorded data (it probably is recorded already, for that matter), and use that.

It’s already recorded on the MOT, but you don’t require one for a car newer than 3 years old.

I think using the odometer makes sense, since you need to take your car in for periodic checks anyway it would be easy to tack that on. I doubt winding back would be a large issue since there are already economic incentives to do it for better resale value, but it isn't really an issue afaik.

Modern odometers are digital and cannot be rolled back.

Sure they can, almost everything in car is hackable with enough effort, look at after sales chip tuning. This would be about billions, so a great motivation.

There may be some tamper-proofing possible to thwart most of folks, but we talk about government, not really the champion of technological excellence.

Surely each individual car owner is not paying billions is taxes. And the people who are making billions (e.g. by distributing services to do this) are a lot easier to go after.

I actually made a post a few years ago about how the UK could look to replace fuel duty as cars move away from ICE.

Fuel duty is a huge source of revenue for the UK government. I remember reading that to replace it solely with a rise in income tax it would require taking the base rate income tax from 20% to 24% at least which is huge.

It has been fun for everyone who was charging their EVs with their solar panels.

it was never going to last forever if EVs became popular

the treasury simply needs that fuel duty revenue

(and the VAT you then pay on the fuel duty..!)

That didn't take long.

1 hour ago | parent | context | edit | on: UK electric car drivers should be charged per mile...

Cars without brakes should have even lower taxes ;)

ICE cars create costs for society in terms of pollution and health issues.

According to an estimate, 5 million per year are killed by pollution from fossil fuels[1].

And that's not even measuring the impact of global warming, deaths from heat waves and hurricanes, the geopolitical dependencies on Russia and the energy needed for AC.

So how about that 5 billion shortfall is made up by taxing ICE cars to encourage them to buy EVs?

[1] https://www.theguardian.com/environment/2023/nov/29/air-poll...

It's true, externalities such as respiratory issues and climate change caused by polluting vehicles should be priced into schemes such as this.

Not sure why this is an unpopular opinion.

Reply on news.ycombinator.com