They're semi-trucks being towed? Lot easier to do this than multiple trailers.
What is this thing?
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A semi is rated to tow tens of thousands of pounds, so this is absolutely nothing for one to do. And sometimes you need to transport multiple semi's to a destination but don't need multiple drivers to do it. This is probably the easiest/cheapest way to do it.
40,000-50,000 pounds is a standard load. 80,000 combined weight is what they don't want to be over when they hit a weigh station.
When a truck loves another truck...
In all seriousness, here in Texas is common to see this going 70 MPH on I30. Yes, it is terrifying.
Semipede
Mating season I guess
See this a lot in Wisconsin. Delivering trucks.
It reminds me of the cover of the Aerosmith album Pump

It's a truck-truck-truck truck, towing a truck-truck truck, towing a truck truck, towing a truck. Duh.
You know, I watched The Simpsons in the 90s and 00s, too.
Children, this is how F-250s are created
I snort laughed
They're just very horny trucks.
The initiated among us call it a turtrucken.
The cover of Aerosmith's Pump - The Next Generation
its not complete. once enough are on it makes a circle and the front truck mounts the last truck.
This is actually how baby semi trucks are made!
Seriously though, they're just hauling semi trucks: It's more cost effective to tow multiple semi trucks with a semi truck than it is to deliver each one by driving it.
Looks like someone knew the Google maps car schedule for that road.
A truck centipede.
Semi centipede?
They've already got wheels, seems silly to put them on a trailer and pull a completey different set of wheels when these work fine.