[b112]

It may be efficient in Europe, but when trucks drive long distances (are you sure you understand how far?), speed makes a huge difference.

You'd literally need to build more roads, as long haul trucks would be on the road, literally, for an entire day longer per load. Speed is efficiency.

A lot of driving is actually done at night. Fewer cars.

[crote]

> You'd literally need to build more roads

Not as much as you'd think, though. At higher speeds you need more distance between individual vehicles, as the vehicles need significantly more time to stop. The rule-of-thumb is that you should keep a three-second gap between vehicles - which if followed would mean speed is completely unrelated to road capacity [0].

The higher speeds are also going to lead to more frequent and nastier incidents, which means more traffic jams. Once the roads get full lower speeds might even result in a higher average throughput!

[0]: https://www.physicsforums.com/insights/analysis-road-capacit...

[Xss3]

Efficiency is higher at slower speeds because of air resistance increasing exponentially rather than linearly.

Resistance at 60 is a huge amount higher than at 50.

Go 10% faster if you want, but you'll use 30% more fuel over the same distance.

Numbers are approximate.

[b112]

Hence the talk of aerodynamic design.

The numbers you quote don't show math, and even if they did, the math is different for each vehicle airflow.

Regardless, efficiency has many properties.

Time means more labour cost + cost of spending another day on the road, plus time not shipping something else.

I sometimes, in my car, drive from Quebec to California. It can take an extra day to make this drive, if I must drive slower due to weather, traffic, or construction.

EG 60mph vs 80mph average (yes, average without stops).

A little more fuel pales in comparison to these costs.

[timbit42]

Fuel is a lot more expensive in Europe, almost double.

[dewey]

Shouldn't the trucks be more used for "last mile" operations from the cargo trains vs going very long distances and needing to go very fast? Seems like that would be the more appropriate solution.

[porphyra]

Interestingly, the freight train network in the US is a lot better than that of Europe and Asia. A much larger fraction of goods is delivered by train in the US at a higher efficiency.

https://www.marketurbanist.com/blog/why-americas-freight-tra...

[crote]

> the freight train network in the US is a lot better than that of Europe and Asia

That depends a lot on how you look at it. The US got screwed by geography and doesn't have a lot of inland waterways. This means that rail freight is the only viable option for a lot of bulk cargo. The US is sending an awful lot of coal and grain via train, but in Europe most of that is done by river and canal.

The US also has a rather poor record quality-wise. Electrified rail basically doesn't exist, precision-scheduled railroading has made delivery times a joke, the infrastructure is crumbling, and freight trains are utterly incapable of playing nice with passenger rail. Heck, they are literally running trains which are too large to fit on the railways! It has been optimized for dirt-cheap bulk transport and as a result it isn't really capable of doing anything else.

The fact that US railways have such high tonne-miles, despite the state of the railways, says more about the complete lack of competition than it says about the railways.

[JumpCrisscross]

> US got screwed by geography and doesn't have a lot of inland waterways

We have some of the largest inland-waterway networks in the world. We just Jones Acted ourselves out of being able to use them.

[toast0]

Cargo shipping is a mix of all modes. Rail has a lot of good things going for it, but capacity is limited, routes are limited, speeds are limited, and trains are fairly inflexible.

Trucks can be used for a lot more things. They might not be ideal for long distance routes, but they're often used for them. Dock to dock time is often going to be far less with long haul trucking than truck to local train depot, rail to remote train depot, truck to remote dock.

It's also much harder to build rail capacity than road capacity; certainly that'a a function of our government, but someone with one container to move has to work within the environment.

Trucking also feels like it has more agency. If your truck fails, you can send another to pick up the load; if your train fails, you're at the mercy of the railroad. If there's disruptive weather in the path, a truck can drive around it; almost always a train will have to stay on its route, and may need to stop for the weather to clear. If the shipment needs to be recalled, the truck can turn around; you might be able to get your load off the train, but maybe not?

[jorts]

I’d have to imagine the folks in this industry have done enough analysis to figure out what is most cost efficient.

[mbreese]

I have no specialized knowledge in this, but I don’t think that cost efficiency is the primary reason for using trucks over trains. Because, if it was, rail with last mile by truck would probably win. Rail has a very low cost per mile by weight rate. But, it can be slow. Particularly when you consider that there are only a few routes across the country (across the Rockies), and trucks can go directly from point A to point B without needing to connect to a rail hub at both ends.

In someways it seems similar to why the hub and spoke model has fallen out of favor for airlines. It might be more efficient to have one large flight between hubs and two small flights to regional airports, but passengers would rather have a direct flight.

[petre]

Maybe, but the semis are also faster due to bureaucratic reasons involving train operators, which are mostly state owned companies in Europe. So p derivate enterprises just hire a trucking company to deliver goods faster. Rail is mostly used for cement, oil products, fertilizer and grain.

For instance in my country the public train company is absolutely brain damaged as it doesn't have enough bike transportation spots (only some trains do). There are even trains with a bike symbol that you're not allowed with a bike on. Thanks to the EU Green Deal they are now forced to provide them.

[bigfatkitten]

> You'd literally need to build more roads, as long haul trucks would be on the road, literally, for an entire day longer per load. Speed is efficiency.

Only up to a point. The relationship between speed and fuel burned is not linear, and fuel is the largest cost.

The legislated maximum speed for heavy vehicles in Australia is 100km/h, but most major fleets electronically limit their vehicles to 90 for efficiency reasons.

Every extra km/h over 90 has a negligible impact on trip time while imposing a large penalty in terms of fuel burn.

[seanmcdirmid]

Truckers are also limited to how many hours they can drive per day, but not on how much distance they can cover, so more speed is an optimization to the driver’s paycheck. Autonomous trucks wouldn’t have that problem and could maximize efficiency.