is it for real?

I tried counting the number of cars on the train, and did pretty good as long as i was looking at the right side of the screen where it wasn't as blurry), but lost track after 115, of which there was still a decent time left of the train passing by. Perhaps 150-200 cars on the train, but in any event, i looked up the longest freight train, and guinness said that the longest train was 682 car-lengths long, (here's the link: http://www.guinnessworldrecords.com/content_pages/record.asp?recordid=43842), so I'm pretty sure that it was real, though i don't know haw fast such a train could go, so maybe it was spliced together.

1) Just look at the sky on top of the screen.
2) the lighting on the wagons never changes abruptly.
3) the speed of the train accelerates progressively.

Any kind of editing would have shown some irregularities at some point if it were to give the appearance of a long train.
Besides, would the director have gone as low as editing this footage to impress the audience? Perhaps...

Koyaanisqatsi rules!

Look closely. You will see:

1) The visible cargo on top of the trains repeats every few cars.
2) So do the color schemes of them.
3) The clouds in the sky move a bit forwards, then backwards, then forwards...

I've seen trains about 70, 80 cars long where I live, but considering the size of these I doubt they would use as many as 150 or 200 wagons.

[deleted]

Trains of that length aren't that uncommon, even in the U.S. Try living near the tracks of a major freight route, you get trains going by at 60+ mph that can last a minute or more. Especially at night. When you're trying to sleep.

This segment is comprised of one continuous shot of a fairly long train. I have watched this movie dozens of times over the years, and I can verify observations made by others who have posted on this thread, that the train gains speed as the scene progresses, and that there are no special effects, cuts, clips, jumps in this particular sequence.

The DVD scene selection title is "Train to Sao Paulo." The train is certainly in South America, most likely Brazil, and by the looks of it, very probably loaded with coal. It is somewhat unusual for trains in the U.S. to be that long, but not entirely unheard of.

For example, I have seen coal trains come south from Colorado into Amarillo, Texas, cross under Amarillo Boulevard just east of McMasters, curve around to the east through the downtown switch yards, then snake back around to the north towards the power plant. By the time the lead engines on the train glide under Mirror Street overpass, the last coal cars have yet to pass under the Boulevard bridge, three miles back.

From coupling face to coupling face, the coal cars are about 60 feet long, so that means these Colorado coal trains must number 250 cars or more.

Interestingly enough, I could not find anywhere on the internet a figure for the amount of coal consumed by the Harrington Electric Plant north of Amarillo, but according to several environmental websites, in 2006 it produced 8,454,511 tons (!) of carbon dioxide, along with 21,235 tons of sulfur dioxide, 13,228 tons of nitrous oxide, and 289 tons of mercury.

So any way you figure it, that's a lot of coal! No wonder the trains are so long.

"Unit trains" (also called "block trains"), that for example aalways carry coal from one mine to one power plant, can be very very long.

Usually all the cars in such purpose-specific trains remain hitched together all the time, and the train travels on a dedicated track. Often the entire track is almost brand new, with only very minimal curves, so it's possible to make the train extremely long (thus having to pay fewer railroad workers per ton of freight moved). As it's often the case the entire train was purchased all at once, it's fairly typical to see all the cars (or "wagons") look pretty much the same. And as these trains travel only from the same A to the same B and only on dedicated tracks, you're not likely to see one up close and personal, not even if you live near a (general purpose) train track.

(Another film where you can see a "unit train" in action is "Khadak".)