back
112 comments
> At 0.5 mph differential, the overtake takes 291 seconds — over a minute of blocking the outside lane. Annoying, but it gains the driver 5.0 extra miles across a working day.

The driver gets there 5 minutes earlier in exchange for causing a 7-km tailback multiple times per day? That seems like exactly the kind of thing that should be regulated away: the truck in front is limited to 90 km/h, you're limited to 90 km/h, you should expect to travel in convoy with that truck even through manufacturing tolerances mean your limiter is actually set to 90.5.

If the 0.5 km/h is actually valuable to the trucking industry, they can invest in more precise limiters at scale.

> Most assume the truck driver is being inconsiderate.

From the article. Then goes on to show exactly how they're inconsiderate with maths. How they're not seeing it is baffling.

From a commercial perspective, you would think the fuel savings from slipstreaming would more than make up for those five minutes.
>>That seems like exactly the kind of thing that should be regulated away

Yes, and the regulation should NOT be limiting passing or requiring the slower truck to brake

It should allow a "Push To Pass" button that allows a 10mph boost for enough seconds to make a pass in a reasonable amount of distance so as to not create problems for other traffic.

Current technology would allow these to be easily limited to X uses per hour/day and even geo-fence the usage for safe zones (use could even be limited to passing lanes so the truck being passed cannot start a drag race to stay ahead). They could even require connectivity and disable it in poor road conditions.

The real people being inconsiderate are not so much the truckers (particularly the slower trucker failing to yield and let the other one pass in a reasonable distance), as it is the regulators who created this mess.

> That seems like exactly the kind of thing that should be regulated away

This is regulated via "no overtaking by trucks" [1] signs on portions of road that are susceptible to formation of queues, or more dangerous road conditions.

P.S. To bundle some replies:

> but they only apply during busy hours

Don't remember ever seeing the time interval next to these signs. They are tied more to the location than the time. But that's not bad? The goal is to avoid the worst issues, not to force trucks to drive in an ordered line for 8h straight. Traffic lights also sometimes turn to intermittent yellow late in the night. Why spend a few minutes alone in the middle of the street for a red light?

> Does it still make sense for that to be "default allow?" Why doesn't the trucking industry lobby for every Truck Overtaking zone

The default should be the the one that applies most of the time. Today that's the "allow overtake". I'm allowed to very slowly overtake in my car. And I've seen this when I was driving right at the speed limit and someone else was overtaking at something like 1cm/s. It was painful to watch, at some point I just slowed down a bit to let him get in front and release the left lane.

If you ban truck overtakes and allow them only in specific zones, you'll quickly have kilometers long truck queues that never get drained. For an overtake that takes 1 min at 90km/h the trucks traveled 1500m. Many highways are 2 lanes so just one slow truck on the right lane and one slow car on the left lane screw the entire highway. Those costs go to you whether you're in your car or buying something those trucks deliver.

[1] https://media.gettyimages.com/id/1728143251/vector/no-overta...

It kind of annoys me that the article says the people trapped behind the trucks are just inconvenienced, but the truck driver gains time and money. Considering commuting to and from work is what most people are doing on the road, that is exactly time and money. It really could be seen as truck drivers stealing dozens, if not hundreds, of minutes from other drivers to give themselves 5 minutes.
I was reading the NASA truck aerodynamics thread earlier and realised that commercial freight is one of those fields that touches everyone's daily life (everything you own arrived on a truck) but sits in a complete knowledge blindspot for most people.

I work in fleet fuel efficiency and wrote up the foundational mental model, covering why trucks weigh what they weigh, why they're all doing exactly 56mph, why diesel is so hard to replace, and why 1% fuel savings matters when you're burning 43,000 litres a year.

This is the first in a series, there's already a 2-part deep dive on hydrogen up as well. Tried to keep it accessible without dumbing it down.

You open with

> Every driver in the UK has experienced this. Most assume the truck driver is being inconsiderate.

But then go on to explain how that is exactly true. The truck driver is taking time from *all* drivers on "roughly 4.5 miles of dual carriageway", just so that they can end the day 5 miles ahead.

> The five minutes of inconvenience to you saves them meaningful time and money over the course of a day.

It's five minutes of inconvenience to *everyone* on that 4.5 mile stretch of highway that nets the truck 5 minutes (5 miles ahead at ~60 mph). That's a very selfish and inconsiderate outcome.

A very well written article! I'd add a few things though.

> Every kilogram you add to the vehicle is a kilogram you can’t carry as freight.

That is only relevant when hauling bulk loads, think ore, soil and the likes, or you're carrying a trailer full of IBC liquid containers. I worked in stage lighting stuff, our trailers were at least 3/4 foam by volume, they didn't even come close to maxing out their weight.

> A battery pack storing equivalent energy would weigh on the order of 16 tonnes at current lithium-ion energy densities.

You don't need to haul a fully equivalent battery. Drivers have to have their mandatory rest breaks of 30+15 minutes here in Germany - that's enough to charge 300-400km of range. Additionally, they can be charged at loading docks, provided the freight base or the customer have chargers set up.

> For a driver paid by the mile, or on a delivery schedule measured in minutes, that overtake is rational.

Payment by mileage is illegal in Germany, as a trucker you need to be paid by the hour and you need to be paid under German minimum wage law as long as you're physically on German roads. Trucker companies from Eastern Europe are infamous for evading that, but as our customs enforcement (who also do the road inspections for rest breaks and minimum wage) ramps up, it's getting better.

The remaining problem are the dispatchers, quite a few of them hand out routes to their drivers that are barely achievable when operating legally (i.e. trucks with working speed governors, drivers taking their rest breaks). Competition is fierce, there used to be talks about passing laws to force dispatchers to not give barely-legal orders but I'm not sure where these went following our government's collapse last year.

> An electric drivetrain achieves around 90%, so you only need roughly 1,600 kWh of battery capacity for equivalent range.

Yup, and most importantly, you mentioned regenerative braking cutting down on brake wear - but it's not just cutting down there, the truck can actually save a fair amount of energy as well, at least outside of highways where the truck is mostly just coasting along.

Trucks, given the right infrastructure, are also viable for running them electrically in the mid-range nowadays as a result.

this is well written. thank you - you broke down the economics nicely.

I do think maybe with a hub & spoke model - big trucks move loads to hubs -- then smaller electrified trucks cover the less than 200 miles from hub to spoke. electrified smaller trucks and vans are already economical today.

you get to benefit from using diesel for long haul routes - while also - better economics on the electrified front i.e a hybrid model

This is excellent, I'm really looking forward to your piece on fuel additives.
Really interesting. Much thanks!
Do you have an RSS feed for your blog?
> This isn’t advisory. It’s a physical limiter in the engine’s ECU. The truck cannot go faster.

I live in Latvia (in the EU) and see a significant part of our ARTICs on the roads go well past 90km/h daily. I presume their fleets do monitor the speed and alert the driver if speeding for a prolonged period of time but they are obviously not physically limited. Maybe the limits do come from the factory but get disabled? I really couldn't say.

A recent journalistic investigation uncovered a problem with the weight limit not being followed on a mass scale too. Specifically by our lumber industry whos drivers are incentivized to break the law. Even if you see a dangerous overloaded truck on the road and call the Police, it is likely no action will be taken because there only a couple of units in the country that are equipped to weigh a freight truck out in the field.

Probably the first thing to consider is the trucks have their speed calibrated periodically to ensure the accuracy of their tachographs (in the UK at least) so a truck doing 90kmph may show as 100kmph+ in a passenger car, I know my Volvo is 7% out, and my Seat is closer to 10% out.

That said, depending on the truck, there's fuses you can pull, ECU remaps and even for the older trucks with the magnetic sensor in the gearbox, the trick is/was to stick a magnet on the sensor (with a bit of string, so you can pull it off remotely if you get pulled over). All of these methods are becoming less feasible, as things like the aggregate wheel speed sensors used for ABS get used, you can't just fool one thing now.

As for the weight limit problem, that's a whole other rabbit hole!

Cant they divert them to a nearby weigh bridge and find out?
Tachographs are mandatory and monitored across the EU so I very much doubt that's really happening.
Maybe they should give the trucks a "turbo boost" button that lets them increase speed by something like 5 KM/hr for 120s every 30 minutes. Just enough to allow truck drivers to pass now and then without causing these types of log-jams on the highways, without causing safety problems. I'm sure there's a more correct combination of speeds and times than this.

Sort of like the silly "boost buttons" on the Honda CR-Z [1] or the Elantra N [2], but just lifting the speed limiter for a bit...

[1] https://en.wikipedia.org/wiki/Honda_CR-Z#Powertrain

[2] https://en.wikipedia.org/wiki/Hyundai_Elantra#Elantra_N/Avan...

The incentive for the drivers would be to press the button every 30min, regardless of actual overtaking need. And when overtaking has to be done, the button would probably be in cooldown, solving nothing.
For people that want to make the calculation: A truck does not need a 15 ton battery. In Europe, we have mandatory breaks for truck drivers. So you need a battery pack for max 400km of range, let's say 500km. When you have a break, you charge. For this, you need like 1500kWh battery pack, which weigths like ... wait, 15 tons. But this is not entirely correct, the real values reported are between 120-150Kwh/100km, that means a half of the stated number, 7.5 tons for the battery pack.
The (bad) justification for overtaking seems a much better justification for the slower truck to fix their calibration and go faster.

Lots of good info but it all feels a bit like it is being used to create a "just so story" to support whatever the current status quo is.

> Rail is superb for what it does: moving bulk commodities... The problem is last-mile.

Before around 1950x-1970x rail networks were more dense (at least in Europe) - any significant goods source/destination (like a warehouse, a factory e. t. c.) had a railway spur. Lots of rail tracks / spurs were abandoned /removed when it was widely believed that trucks are the future and railways are outdated.

If all these spurs were kept last mile problem would not be as bad for railways. Also electric trucks are well suited to solve this last mile problem.

The article makes it sound like the Tesla Semi is physically infeasible. Yet, it is in active use on a sufficient number of long-haul routes that ignoring this proof of existence undercuts some of the central points the post tries to make.

The combination of higher efficiency, regenerative breaking, and some regulatory wiggle-room such as slightly higher allowable gross-weight (2000 lbs in the US, and 2000 kgs in the EU), together with reduced maintenance cost and time significantly affect the economics of trucking.

As regulatory frameworks price in more externalities of internal combustion engines, such as the climate and health effects of their emissions, burning diesel will no longer make economical sense. All road transport will end up being battery-electric. The declining cost of owning and operating electric vehicles compared to internal combustion ones will reach this point even without regulatory changes, just at a slower pace.

Argh the liberal admixture of different units (mpg, kg, L, hr) in the first table really brings home that this is a UK piece.
> Driver training that closes the 15–20% gap between the best and worst operators in a fleet.

As a naive non-trucker, I'm surprised to hear that the difference between the best and worst operator is this significant. I realize it's a bad look, and shows I thought this was a low-skill job, but I'll be honest and try to call out my own prejudice. It's cool that skill actually does have a large impact here.

> The truck cannot go faster. Floor the throttle at 56mph and nothing happens. The fuel injection is electronically capped.

Man, that's kindof scary -- if for some reason the truck legitimately needs to go faster (eg, escape a warzone, a flood, a wildfire), it cannot do so. I'm sure this was a calculated design decision, but on the surface I'd prefer if the speed was logged and then checked at regular intervals (perhaps with automated reader). That would also allow for easy updates to the limit, tighter restrictions in specific areas, etc. I wonder what all the factors going into this design decision were.

Interesting, thanks!

One thing I'd update is that early in the article you say that for switching from diesel to lithium-ion, "It's 16 tonnes of payload that disappears".

But then later you take engine efficiency into account and say it's "about 6.4 tonnes of battery".

So the claim that it would ever reduce payload by 16 tonnes seems incorrect, and not everyone is going to read both parts.

> An electric drivetrain achieves around 90%, so you only need roughly 1,600 kWh of battery capacity for equivalent range. At 0.25 kWh/kg, that’s still about 6.4 tonnes of battery — roughly 18 times heavier than the 350 kg diesel tank and fuel it replaces

This misses the fact that the motor and transmission on an electric truck is lighter than the diesel. This doesn't completely negate the issue but it does help and is not mentioned.

The 15 liter diesel engine is about 3500 lbs and the transmission with many gears is another 700 lbs.

The Tesla Semi has 3 model S motors with single speed transmissions each one is about 300 lbs with inverter so there are at least 2-3000 lbs weight savings in the drivetrain to consider.

In the US Electric semis get an extra 2000 lbs payload allowance too too so they can be 82k lbs total rather than 80.

>. That’s roughly 28 to 35 litres per 100 km, or around 30 litres per hour at cruise speed. This is not a misprint. A truck burns in an hour what a small car burns in a week.

Let me paraphrase - a truck weighting 25 times more than a car burns only 4 times as much fuel per 100km at corresponding cruising speeds.

> At 0.25 kWh/kg, that’s still about 6.4 tonnes of battery — roughly 18 times heavier than the 350 kg diesel tank and fuel it replaces, and 6.4 tonnes of payload that disappears from every trip.

And how many tonnes of internal combustion engine, gearboxes and plumbing? It is not an insignificant matter

Is this correct — HGVs can go faster on dual carriageways than motorways?

"UK speed limits for heavy vehicles are also more complex than most car drivers realise. Articulated trucks over 7.5 tonnes: 60 mph on dual carriageways, 50 mph on single carriageways, 56 mph (limiter) on motorways"

Not able to find a source that verifies that

> The five minutes of inconvenience to you saves them meaningful time and money over the course of a day.

Assuming my time and everyone else stuck behind them combined is far less valuable than the truck driver.

Long haul trucking should be illegal or effectively eliminated by a carbon tax. Use trains for long hauls.

He even said the problem with trains is last mile. Last mile short haul trucks can be and are electric.

It's weird he laid the groundwork for this argument, but he isn't making this argument.

Fix the infrastructure issues that make transferring from rail to truck difficult. Yes, that's challenging and expensive. Guess what else is? The status quo, and the effects of climate change.

>Most assume the truck driver is being inconsiderate.

You could probably add a whole section of specifically learning to drive a car with trucks on the road to driver education programs and it would do wonders for traffic.

>Anti-idle ordinances exist in several US states and EU regulation is moving in this direction.

Yep, grab a sleeping bag or take your clothes off and use evaporation cooling on yourself. The good news is that car/van camping stuff can apply to trucking as well and that is fairly popular these days.

Another option is simply having places to sleep outside of the truck that are powered by solar/wind and don't cost anything to truckers, but that's only viable when we actually care about reducing emissions over profit.

>Every kilogram you add to the vehicle is a kilogram you can’t carry as freight.

You can save a bunch of weight by not having the sleeper cab if you can readily stop somewhere for a safe place to sleep. There's quite a bit of frontier savings you can do by externalizing costs of transporting stuff to other industries (aforementioned free hotel rooms) and getting tax payers to pay for it, which makes a ton of sense here since trucks are transporting all of the food we eat.

Why is fuel consumption 5x more per mile but 10x more per hour, if the trucks are moving more slowly than cars?
It seems like trucks are a use case where battery swapping would make a lot of sense. Unlike with cars, the battery doesn't need to be a structural element, and there's much less need for it to be a strange shape, as in some cars.
Also, heavy lorries are responsible for almost all of the road wear, and are therefore heavily subsidised by other road users. The whole system feels like insanity, if you ask me.
What about catenaries? Trucks aren't going anywhere. I'm guessing 95% of lorry traffic is on ~5% of roads, small battery for the last mile and power lines for long distance.
Tangential, do vehicles detect motion by crosswind or road camber and compensate? I saw some social media post of lots of trucks toppled over by crosswind.
I'd buy into the efficiency and economy arguments more if the truckers would stop dumping gallons of diesel on the roads.
The mix of imperial and metric units in this article was confusing.
great article but the 44 tonne limit is not "physics", it is regulation. if an electric truck would be allowed to weigh 5 tonnes more all these calculations would be different.
How is fuel consumption per mile 5x but fuel burn per hour 10x?
the one being overtaken could release the throttle for a moment...

THE ONE BEING OVERTAKEN COULD RELEASE THE THROTTTTTTLE...!!!

:)

> A diesel fuel tank for 400 litres of diesel weighs roughly 350 kg (the tank itself is relatively light; diesel is 0.84 kg/L). A battery pack storing equivalent energy would weigh on the order of 16 tonnes at current lithium-ion energy densities. That’s not just additional weight. It’s 16 tonnes of payload that disappears.

And yet, electrical semis exist that come without 16 ton batteries. The fallacy here is that most of the diesel is used to heat the universe rather than move the truck. Truck engines are relatively efficient but it's still a combustion engine. EV trucks are now a reality.

Mercedes-Benz’s eActros 600, one of the flagship battery-electric long-haul trucks now in series production, uses *three 207 kWh LFP battery packs for a total of 621 kWh of installed capacity, and under realistic conditions can deliver about 500 km of range on a full charge with a 40-ton gross combination weight, with opportunity charging in driver breaks enabling well over 1 000 km of daily travel. That's 4-6 tons of battery, not 16.

Volvo Trucks’ current flagship, the FH Electric, has 360–540 kWh of batteries (four to six packs) and achieves up to ~300 km of range for typical heavy-duty operation, and its forthcoming FH Aero Electric long-haul variant is being announced with ~780 kWh battery capacity targeting ~600 km of range. That's around 3 tons of battery.

The weight goes at the cost of the useful load. Though the EU allows an extra 2 tons for new energy trucks. And of course a lot of trucks aren't fully loaded typically. Also, the weight limitations have a lot to do with safety issues related to diesel trucks and their brake systems that electrical trucks have much less. Regenerative braking and lots of torque at low speeds mean that they could move a lot more weight safely than currently allowed. And adding more axles to distribute the weight can address any road damage concerns.

With mandatory 45 minute breaks every 4.5 hours, trucks can just top up as needed. With normal truck driver hours that's 1 or 2 breaks in a working day. There's a growing amount of chargers all over Europe and these things routinely drive all over Europe from Scandinavia to Iberia to Balkans and everything in between. There are of course still many places where more/better chargers are needed but these ranges are usable and practical enough that you can get loads from A to B in most of Europe with only minimal delays relative to diesel trucks in terms of charging time losses. It's early days and charging infrastructure is rapidly being improved. But the point is, that electrical trucks work just fine today. There are no fundamental real load or distance limitations here. But of course more infrastructure is needed to scale.

Lighter batteries will make trucks slightly more efficient. But price and longevity matter much more. Sodium ion with its well over a million mile lifespan looks like it should revolutionize trucking over the next decade. LFP is commonly used today already. NMC is lighter but has a lower lifespan.

.
These large trucks must go. While the mentioned numbers make some economic sense (cost per tonne transported etc.), the road wear is excessive due to the fourth power law. Most cargo can be split into smaller chunks.