Considering that only the Pullman actually opeated all the way (as was mentioned in an earlier post) that there were no coaches for at least part of the run, and I've seen public timetables attesting to this, one can consider the Interstate Expres as an "all sleeping car" train (after all, the all-sleeping car Panama Limited [before combining with the Magnolia Star]did include a parlor car part of the way for early evening short-trip travelers), and while one could place the Interstate Express in the same era as the other great all-sleeping car trains as the Panama Limited, Super Chief, 20th Century Limited, Broadway Limited, Pittsburgher, etc, the Interstate Express would have had to have been the most "downmarket" of the genre, with no diner or other amenities, but a lot of head-end traffic. There was an article a few years ago on the Interstate Express in "Railroad and Railfan" magazine.
Back in the 1960's while I was a student on day trip between Jersey City and Allentown, a trainman told me that in spite of the "apparent gap" in CNJ passenger service between Allentown and Jim Thorpe (as alluded to by a previous post: the night-time Jim Thorpe-Wilkes-Barre "shuttle"), an "all-rail" route on the CNJ was actually possible up on til the Aldene Plan from JersetyCity all the way to Wilkes-Barre by taking the "Queen of the Valley" from Jersey City and detraining at Bethlehem (short of Allentown), have dinner a few hours in Bethlehen, then walking over to the Reading (not CNJ) station in Bethlehem where the train would actually stop and you could then board the rider coach (again as alluded to by a previous post) and actually pay an officially recognized tariff cash fare to the conductor to continue to Wilkes Barre. The only intermediate stop would be Jim Thorpe.
Apparently the reason that the train appeared in CNJ timetables only as a Jim Thorpe - Wilkes-Barre "shuttle" was probably that you had to board the RDG rather the CNJ station, so in the era of discouragement of pasenger service, the Bethlehem stop was simply not shown, but the Jim Thorpe - Wilkes-Barre "shuttle" was! Previous to that info from the trainman, I had always wondered why such a middle-of-the-night service between only end points could make sense on an isolated service removed from the major passenger service areas on the CNJ. I was eventually intending to make that trip via Bethlehem in a few months' time, but I missed out when I did not notice when the Aldene Plan appeared "suddenly" in my still innocent student state. Apparently, the Pennsylvania authorities did not immediately approve the discontinuance of the "published" timetable (ie Jim Thorpe - Wilkes-Barre "shuttle"), so while the through rider coach from Bethlehem was discontinued, this non-stop service for a few more weeks continued on the night run between the two towns using a single RDC (without mention any more in the CNJ public timetables), but with the difficulties of accessing Jim Thorpe at an ungodly hour from New York, I even missed out onthat opportunity. Considering the hours and only end points, as well as no "official" information on the service in the public timetables, I wonder how many, if at all, pasengers used the "real" RDC "shuttle", as opposed to the through train that had been carded as a "shuttle"!
So as a through train at least as far as Wilkes-Barre from Philadelphia coach-only, yes, the Intestate Express, having died a slow death starting 1951 as described in an earlier post, finally died at the implementation of the Aldene Plan, though I doubt the name was even called that in its last years.
Vytautas B. Radzivanas
Perth, Western Australia