Back in 1976, shortly after the conclusion of the nation's first Energy Crisis, an ancient old codger - who then was nearly as old as I am now - wandered into a toy train store that I managed* and proceeded to hand out copies all around of a booklet detailing his proposed grand solution to our energy ills: Helixtram.
*(to my present embarrassment)
After an instant's review, I came to the conclusion that the tightly wound tube of his brainchild was the product of a more loosely wound mind.
Surely any level-headed person would be able to recognize the glaring design flaws in Mr. Jacobson's setup, yes? For instance, looking at Figure 4 below, if you lived in, say, the San Fernando Valley - where crack houses and garage porn studios abound - wouldn't you be a just a bit concerned about where that capsule presently whizzing by your bathroom commode had been? Ick!
That aside, one would suspect that installation nightmares would continually arise in highly crowded urban areas. A suburban arrangement (Figure 4) would be an easy-peasy proposition compared to what contractors would encounter when trying to optimally locate a 155mm howitzer for blasting right-of-way holes through row houses and highrises. Of course, these days he could avail himself of one of those compact war surplus Death Rays in a Jar to do the job, but this was only a futuristic dream 40-odd years ago.
Undoubtedly, his worst error shows up in the cover lever, which makes it clear that he was relying upon proprietors and customers of model train stores to pass the word, and yep, there he was, an elderly fellow from Oak Park, Illinois standing in a San Jose, California train shop. I mean, I honestly cannot remember one instance of a normal person paying the least bit of attention to my personal blabberings about my trains. "Uh huh, uh huh... [checks phone for messages]" Indeed, this seems to be the default response for anyone cornered by a model train nut, so no wonder Helixtram was a bust. Somebody may be able to fix the design - a task presently taken on by Elon Musk, BTW - but you just can't fix model railroaders.
In all, I might have had more enthusiasm for Helixtram at the time had the inventor made a provision for a full bar and perhaps demonstrated a (hosted) working model of same, but no...