They are pushing driverless trains regardless of train lengths, and, on a closed system like a RR, it's actually in many ways, much easier than on much more chaotic roads, and we're gonna have that becoming common in the next seven years, too.

And, if you believe that they won't adopt and implement automation, if and when that technology proves cost effective and practicable, if we were just to allow the RR's to run longer trains, then I've got a real big bridge to Brooklyn, to sell you, real cheap, cash only though......

Longer train issues have been about two major factors on the public impact side, derailments because of extreme L over V forces, break in two's, and blocking crossings for an eternity. The first two have occurred, with some frequency, and have been attributed to train length issues. I've still not seen good "evidence" on way or another on that.

I don know that I've been through this longer train nonsense both as an RR engineer, and as a transportation economist, several times in my long career. And, my experience from both is that about every 20 years, a new batch of MBS's comes out of grad school, with their head full of theory, and they go out an figure out that longer trains theoretically cost less to run (on paper, in nothing goes wrong).....and we go through another phase of this "long train" nonsense.

My empirical experience and aa fair amount of data and studies suggest that this longer trains saves money "on paper" nonsense, is just that, since as train lengths grow, often nothing does go right.

There is actually a lot of evidence that suggests that after a certain length, that costly problems increase by a factor greater than the purported cost "savings"/ These costs of things "going wrong" come from the basics of train physics like more broken knuckles and pulled drawbars, more L over V accidents and derailments, and of course, going dead on the law from additional delays, being unable to make meets, inability to maintain speed on grades, tying up track capacity, the difficulty of yarding those "super" trains, or doing set outs and pick ups with a forty car handles, to block trains "on the road" (excess pick ups and set outs en-route blocking and re-blocking, to have road crews do it, and reduce the need to yard trains, another looks better on paper theory....).

So, like a normal kidney stone, this too usually passes, after a period of severe suffering and pain from those experiencing it.......