This grows out of the thread on remnants of the Erie main line: I believe one of the reasons EL routed through freights via the former DL&W east of Binghamton rather than the former Erie was New York State's full-crew law requiring six-man crews, involving an additional brakeman. Trains on the former Erie would have had to have the extra brakeman all the way from Croxton (not much to be saved by having him board at Suffern), but via Scranton they could get almost to Binghamton with a 5-man crew. I'm wondering now whether they were able to get as far as Binghamton without the extra man, or did a "swing brakeman" have to board at the state line, a few miles east of Binghamton? The PRR had a similar situation on trains from Enola to Elmira, which entered New York 3 miles south of Elmira and had to stop at Fassett, at the state line, to take the swing man aboard for the last 3 miles; a trackside shanty was provided for the brakeman who bailed out at Fassett southbound to wait for the next northbound.
I don't think EL or DL&W had to have a swing brakeman board going west to Binghamton. The last station to the east was Hallstead in Pennsylvania, about eleven miles from Binghamton. On the other end of the state -- was it Niobe? -- they did have the swing brakeman board going east to Hornell and get off going west.
Having read a lot of emails from former EL employees, I think early on most of the through freights did go via the Erie side. One of the reasons often cited for the switch to the former Lackawanna side in the late 1960s (despite it having a helper district) was the declining condition of the former Erie main line east of Binghamton. It was not an easy route to maintain and it had almost no on-line industry. With not enough money to maintain both properly EL had to choose either the former Erie New York-Delaware Divisions or the former DL&W Morris & Essex-Scranton Divisons. I don't recall much mention of the extra brakeman being a critical factor.