> Sounds like a waste of human potential

So do pedestrian fatalities.

How many pedestrian fatalities are there due to collisions with trucks going more than 60 mph? I'd guess very few, because nearly all the places with speed limits above 60 mph in the US are also places with few pedestrians. Often they are places were pedestrians are prohibited.

1. reducing speed can improve throughput when congestion is happening

2. nobody should be speeding, especially not in a extra large and heavy vehicle

> reducing speed can improve throughput when congestion is happening

no, consistent speeds improve throughput, jackasses can, and do, tap their brakes at reduced speeds.

I'm sure "Truck speed limit 60 [mph]" is fairly common in the USA, so it's easy to see that could be extended to other vehicles larger than cars.

On the off chance this is misinterpreted by non-US people.

truck here means semi-truck (18 wheeler). aka, these things: https://www.macktrucks.com/trucks/

these limitations are common in the US insofar as many places, particularly more rural areas, it's not safe for these types of vehicles to be going faster. These vehicles require a separate license to operate and have completely different concerns, such as riding their brakes on a downslope causing the brakes to get so hot they stop working and you get runaway semi's that cannot slow down and become dangerous.

That these types of vehicles have specific laws applied to them does not naturally stretch to applying them to 2-axle vehicles since these same dangers flat don't apply to them.

Semi's are required to have properly functioning mud flaps, this in no way implies a corolla should ever be required to have mud flaps installed.

Anyone curious about the brake thing: https://www.thetruckersreport.com/truckingindustryforum/thre...

In the EU it's generally not signed, as the limit applies to the vehicle regardless of the road.

For example, 80 km/h for lorries on the motorway in Germany, otherwise 60 km/h.