Four trains a day each way, plus helpers, some locals and the Maintenance of Way Department. The maximum speed on the Pennsylvania Subdivision was 45 mph.
The D&H was very conservative in its signalling practices, and that resulted in a very efficient railroad when everything else worked right. The Nineveh Branch, and the old Penn Divison south of Carbondale, had automatic block signals for decades. The Jeff had a manual block system and double track when the Erie owned it. The D&H single-tracked it and installed the traffic control system. The first installation of a TCS system on the D&H was around Windsor on the Nineveh Branch in the 1930's. It was warranted by the traffic, and the economies of closing manned train order offices.
The Champlain Division was converted from ABS to TCS around 1965, and all the traffic up there was essentially two freight trains and two passenger trains each way each day. There were very few track retirements involved in that installation, so one would not say that the rail released from track paid for the signal system. That was also the case on the Nineveh Branch, but the economies of single-tracking helped justify the signal improvements on the Jeff.
When the Champlain Division signal project was complete, the D&H was the first railroad in the United States to be covered from end to end with a traffic control system (sometimes referred to as Centralized Traffic Control, a registered trademark of General Railway Signal Co.) It actually extended from NR Cabin just south of Rouses Point, to MO Cabin, just north of Wilkes Barre. The "tag ends" of the railroad, at Wilkes-Barre, Binghamton and Rouses Point, had automatic block signals, as did the Napierville Junction Railway, the Albany Main from DJ to KN, the Fort Edward District, and the joint D&H/B&M Mechanicville Branch from QS at Crescent to Mechanicville West.
The D&H management believed very strongly in the advantages of protection against broken rails and open switchs that was afforded by this signal system. In my experience that faith was justified.