[jonahhorowitz]

> For one thing, they're not speed-limited, unlike heavy-duty trucks in Europe, which aren't allowed to go faster than 56 mph (90 km/h). "So we had to take that in consideration in the design," explained Stadler.

Seems like we could help things a lot by adding this regulation to trucks in America. Slower == better fuel efficiency and safer too!

[uticus]

I'm skeptical, if slower == better fuel efficiency, everything else being the same, the owners would drive slower because that would be money in their pocket.

If you're looking for levers to tweak the system, this probably ain't the one.

[zardo]

Aero drag goes with velocity squared, it is absolutely more effecient to reduce speeds.

Drivers are paid by the mile, if you drive faster your effective hourly pay goes up.

[AnthonyMouse]

> Aero drag goes with velocity squared, it is absolutely more effecient to reduce speeds.

It's more complicated than that. Up to highway speeds, energy costs are dominated by mechanical losses like rolling resistance. Meanwhile engine efficiency is higher at particular engine speeds and power outputs, and higher gearing improves efficiency but only if the engine remains in its optimal efficiency range.

This implies there is an optimal speed before aerodynamic losses become dominant, but that speed increases based on various factors like the air viscosity and vehicle aerodynamics. So the optimal speed will be higher at higher altitudes (common in the western US) and higher for vehicles with better aerodynamics.

> Drivers are paid by the mile, if you drive faster your effective hourly pay goes up.

This is another type of efficiency. It does you little good to reduce your fuel costs by $100 if you increase your labor costs by $200.

[TheRealPomax]

Safer for... who? The 500 miles of mostly empty highway through no-man's land between two population centers? The US, unlike Europe, is mostly empty. You can drive for 5 hours and not just still be in the same state, you're still on the same road.

The only type of road where a regulator would make sense is the kind of road where in the US a regulator makes no sense. Every other type of road already has speed limits at or below what a regulator would be set to.

[eddd-ddde]

Safer for the driver?

[AnthonyMouse]

But then what do you need laws for? The driver already has the incentive to balance their own safety against their other interests. Laws are only needed to prevent someone from imposing an externality on an unconsenting third party.

[TheRealPomax]

Not seeing that one without a lot of words - what highway situation are you thinking of where the driver's safe enough at 50 but not at 70?

(Bearing in mind that US highways are radically different from Europe's)

[eddd-ddde]

I'm not too familiar with US or European highways.

What I am familiar with is lots of curves, inclines, declines. The kind of road where a loaded truck going the limit easily flips into the cliff to the side on the slightest error.

[TheRealPomax]

See, that's a little bit of a problem if you're trying to make a point about why US cargo trucks should have speed limiters then, because: none of those things apply to US highways.

US highways are (by design) very straight, very flat, and very long. And on the rare occasion they're not, there are already speed limits in place.

[wiredfool]

I see plenty of trucks^H^H^H^H^H HGVs going 100+ in Ireland in 120 (auto)/80(truck) zones.

[jandrewrogers]

That would significantly increase the cost. The US isn't Europe, long haul trucking is traversing a thousand kilometers at a time on mostly empty flat highways.

[dghlsakjg]

The speed limit for trucks in CA is 55mph statewide. Doesn't seem to be that big an issue.

[jandrewrogers]

That speed limit is widely flouted on rural highways in California and other States don't observe it at all. Typical max speed limit for trucks in the US is 70 or 75 mph, and a few States have 80 mph.

[kyleblarson]

Because long haul trucking routes never go through Wyoming, the Dakotas, Montana, etc?

[hi-v-rocknroll]

Wyoming's motto should be Drive whatever speed you like!

(It's not an exaggeration because there seem to be about 2 state patrol cars and they're always parked at Walmart getting coffee. If you want to drive 100 as private passenger vehicle, go right ahead. If you want to drive 85 with a rig full of cows, feel free. While Nevada and Montana lost their no speed limit statuses due to federal funding and regulations, but worked around it by issuing smaller penalties.)

[KeplerBoy]

Or it would lower costs because saving gas saves money.

[jandrewrogers]

Increasing the transportation time by 30% has costs throughout the supply chain that greatly exceed the small difference in fuel costs. They aren't even on the same scale. That latency directly adds to the production cost of everything the trucks are carrying.

[KeplerBoy]

In my experience latency has near zero cost and if it has, just use air cargo. It's all about throughput and reliability.