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.

"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 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.

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.

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.

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

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.

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.

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.

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.

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.

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...

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

Edit: Nope, despite the vehicles only being able to propel themselves to 90kmph, the speed limit is indeed 60mph (in England and Wales, Scotland is a more sensible 56mph)

https://www.gov.uk/speed-limits

But...speed limiters effectively limit all heavy vehicles to 56mph[1]

Note that speed limiter are mandatory above 3.5 tons, but the legal limits change at 7.5 tons.

[0]https://www.gov.uk/speed-limits [1]https://eptraining.co.uk/news/article/hgv-speed-restrictions...

> 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.

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!

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...

Your cargo may be reduced but your fuel costs will also be reduced. It’s quite a complicated calculation.

Are you hauling sand? Then you probably can’t spare a single kg of cargo limit. Doing LTL work? Then maybe you’re not totally filled anyways. It really depends. If you’re fine with a 35 ton limit you might be able to make good money with the fuel savings.

Braking distances, road damage (scales with the fourth power of axle weight), bridge limits, etc.

If the limit could safely and appropriately be 49 tons for diesel trucks right now, it probably would be.

Talking about driver education, refrigerated trucks never get to turn off the engine until they unload the cargo. So it's not always for comfort.

> if you can readily stop somewhere for a safe place to sleep

That's the missing infrastructure. Drivers pull over to sleep when they hit their daily driving limit and in Europe most of the places to pull over are plain old parking lots maybe with some services like a gas station. Motels are relatively uncommon. I think losing some of the driving day and paying for a motel more than make up for the benefit of a lighter cab.

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

US gallons are 3.8l

But an RV is not a semi tractor-trailer setup. In fact, crosswind compensation is something I’ve only seen on RVs that don’t involve a trailer (Class A, Class C). And for a semi, how much is in the trailer? Seems a compensation system would need to know that.

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.

> Distribution centres are built around motorway junctions (J24 of the M1, the Golden Triangle in the East Midlands) because that’s where road access is.

But they skip _why_ is that road access and motor junction there. It's there because the government decided building roads was something that was it's responsibility. I know this article is UK focused, but for the US if the government decided to build rails also, then they could put them in more convenient places. Instead they allow rail companies to decide which monopoly corridors the companies get to control.