The midwest.
I’ve seen this behavior many times. I recently saw it a few days ago. Two semis were driving side by side for miles, each going in the low 60s on the interstate and blocking both lanes of traffic heading eastbound. The semi in the right lane pulled off and the other semi (the one that was in the left lane) then pulled into the right lane and spend up to about 70.
So that explanation doesn’t work either that they can’t go faster than 60mph. In this most recent incident, the semi sped up to almost 10mph faster than it was going when it was blocking the left lane.
Maybe in some situations that is what is happening, but that doesn’t explain it.
It’s generally cheaper and easier to ship most things by truck. If you ship it by rail, you simply incur the additional costs of intermodal transport, cross dock operations, etc. It ends up on two trucks and a train instead of one truck.
There are a very limited number of occasions where intermodal transport is economical as compared to just using a truck for North American logistics needs. Very large scale things that have to be delivered in enormous quantities from one set place to another (like grain, iron ore, stuff like that) are well suited for rail, but most stuff, especially manufactured goods, isn’t.
Must be Saturday.
Many? I’d say in this scenario it’s all of them.
I used to do the purchasing of raw materials for a mid-size manufacturing plant and I would never put anything on a train if I could avoid it.
Why? Because for cash flow reasons most companies operate on a “just in time” inventory control basis. You don’t have to pay for anything until you receive it and then it is net 30 days to pay, so you order smaller amounts more often. Much like your household budget, you would not go into Safeway and buy a couple thousand dollars worth of food because you are going to use it eventually, you buy what you need for this week or pay period.
Trains just suck at just in time delivery. I instructed my suppliers after many bad experiences to never put my stuff on a god damn train because you would never be able to nail down when your product would arrive.
We did have a contract for one of the major bulk commodities that would ship by train. I would try to space out the orders so I received a rail car every other week. You know what the railroad would often do? Combine the shipments so I got 6 railcars all at once so they could make money on the combined shipments. I had to rent a warehouse until that contract expired because I could not handle that much stuff at the plant all at once. And then the Chief Financial Officer would be right in my office asking me what the fuck I was doing ordering so much at once!
Next contract we told the supplier that they could rent their own damn warehouse if they wanted, but we were going to be ordering truck load quantities only and expect delivery on time within a week.
I am sympathetic to the issues involved with rail shipments because I was also responsible for the export of container loads of our finished products. But there are real issues with rail if time of delivery is vital. You can get at truck across the entire country in 4 days if you need it. That same truckload might not even get put onto a train in 4 days, it could still be sitting in the rail yard.
This happens to me all the time on I-70 in Missouri (2-lane interstate) when I drive back and forth between Kansas City and St Louis. A line of semis in the right lane, me coming up to pass on the left, and the last semi in line pulls in front of me to pass the others. Most times there is nobody behind me so it seems like the semi driver is just being a dick - if he had waited 15 seconds for me to pass before he pulled over to pass, no problem, but now he’s blocking me and taking forever to get around the rest of the semis. (And yes, they have to pass every other semi on the right before they will get back over.) There is no way this is not done deliberately.
they’re checking each others nuts.
I’ve driven all over the midwest for more than 30 years and I almost never see this. What I see a LOT more often are cars who won’t let you pass. They will speed up as you come up on their left side until they are pacing you, and then you have a choice to either have a little race with them or drop back. I tend to add another couple of mph, once, but if they speed up AGAIN to match that, I just pull out my gun and start shooting. 
I drive on the New Jersey Turnpike and I see it every damned day. Why it’s happening seems fairly obvious to me. The semis in the middle lane want to go faster than the slow ones in the right lane. They aren’t just in the middle lane to pass, they are in the middle lane because they intend to drive faster than all the trucks in the right lane. However, they are semis, so they can’t generally match the speed of car traffic. Result = irritation for everyone on the road.
For people who have never seen this - do you routinely drive on highways that are main routes for semi travel? The turnpike is crawling with trucks, to the extent that at one point the highway actually splits and sends all trucks into one three-lane section and all cars into another three-lane section. The last time I was on the turnpike, there were more trucks than cars.
The OP was about 2 lane interstates where the two semis were blocking all traffic. I’ve seen the right two lanes of a 3 or 4 lane interstate effectively blocked by semis all the time. But they’re not allowed in the left two lanes and they have to do all their passing in the right two lanes so it’s expected. What I haven’t seen is two semis purposely blocking all lanes on a two-lane interstate for multiple miles.
Oh. I’ve never seen that either, but I would guess the same logic applies. The ones in the fast lane want to go faster than the ones in the slow lane, but not as fast as regular traffic. They either aren’t thinking about blocking traffic or they don’t care. This is my theory.
I don’t think that is why they do it. Like I was saying when this happened to me again recently both semis were going in the low 60s. After the one in the right lane pulled off the semi in the left lane sped up to about 70. So it wasn’t because he couldn’t pass, it was because they were blocking traffic.
I can’t tell you the number of times a semi would pull over just as I was about to pass – forcing me to brake heavily – and then pace the another semi for several miles at a speed below the posted limit. It’s happened often enough that it seems unlikely it’s unintentional.
On occasion, truckers (who really dislike bad drivers) will form a trap for a drunk and call the police to come get them.
Otherwise, yeah, it takes a while to pass.
If you’re really seeing truckers doing this on purpose (I haven’t; it’s always just trying to pass other truckers with heavily-loaded trucks), call the highway patrol. This is illegal. And the highway patrol is concerned, because it makes trapped car drivers very upset and they do crazy, dangerous things.
Truckers are like other drivers some with road rage. If it is happening frequently to someone chances are they pissed off another trucker a few miles back and the truckers blocking are “paying back” the car driver. One frequent method of pissing off a trucker enough to radio his buddies is to pass a truck then slow down… and that happens a lot.
I guess if other car drivers have been known to behave like children, I shouldn’t be surprised some truckers do too. And apparently they don’t care about all the other drivers they are inconveniencing because of their petty revenge mentality.
This happens all of the time on the I-15 between Las Vegas and California. I have to make this drive 4+ times a month and this happens every single drive. Drives me crazy, it does.
When I’m Queen of the United States, trucks will not be allowed to pass each other ever. Just one long, stupid truck chain plodding along at 45 mph. I will coast by in the passing lane at normal, decent person speeds. It has been declared!
At least in California (AFAIR), trucks are restricted to the right two lanes. Up here (Washington state), they don’t seem to have that restriction – and we have a lot of freeway miles with only two lanes in each direction anyway.