LV route is now single tracked for most of its length with passing sidings. Sidings can be lengthened and/or second track added as and where needed. Even possible reuse of the old CNJ route could be rehabed for use including double tracking east of High Bridge to accomodate traffic.
THe Erie (Southern Tier Route or Delaware Division or Port Jervis Line) could handle more traffic with additional sidings or even so far as returning to complete double track. THe NYS&W route is probably more now than it ever was even in the 20's, 30's and 40's when it extended to Stroudsburg and Wilkes Barre, connected with the Lehigh and New England, and went to Hanford to Middletown and connected with the NYO&W. It would really need major work to become high speed and major east west freight hauler like CSX to Phila or Albany and west and NS to Allentown and west. At present it can probably handle about 6 round trips a day, tops, including its NJT-NS route Warwick-Campbell Hall-Port Jervis-Binghamton. It could also be upgraded enough to handle limited commuter service to Sparta from either Pompton (rebuild NY&GL to Mt. View) or from Hawthorn to Hoboken. The Lackawanna route west from Dover used to go to Washington to Phillipsburg and to Washington to Portland, PA on what was the original DL&W before EL ripped up from Delaware, NJ to Washington. Then there was the Cut Off, built in the early 1900s from Port Morris, NJ to Slatford, PA where it connected with the "Old Road" via Washington. Conrail abandoned this route outright and ripped up the track. When something like this is removed it is very difficult to replace. NIMBY's, not used to a railroad, not wanting their lives and neighborhoods to change, or have forgotten what it was like when there was a railroad, will try to block its return. Proper planning and coordination of railroads, governments, and shippers can work out a plan that is economically sound, enviormentally safe, and useful for all needs.
My point of view of why there are NIMBYS come from the fact that I grew up in Denville alongside the DL&W tracks from about '46 to mid 60's. Minimum two commuter trains an hour, blowing for the station crossing as well as the two in Mt. Tabor. Plus commuter rush hours on both lines east of town, 8-10 mainline passenger trains (to Stroudsburg, Scranton, BInghamton, Elmira, Buffalo), several local freights to Summit or Boonton and Paterson, and up to a dozen or more mainline freights in either direction all on a daily basis. Never bothered me. Been gone basically since 1961. When I visit the family today the railroad is virtually silent and still, unnoticed. What I raise hell about is the din and roar pushed up by the "sound barriers" along Route 80; if I were still living there I would have been a NIMBY about that not the railroad. Its all perspective.