NS Southern Tier?

Overall, I'd say somewhat less busy.  But you've got to break the Tier into a few segments to compare traffic.  The eastern Tier (old Erie main east of Binghamton) currently only sees a couple of NYS&W dailies but NS has invested a lot over the past several years to upgrade the line in anticipation of more traffic out of NJ (and to free up capacity on its Lehigh Line).

Traffic between Binghamton and Hornell is less than the "old days" since everything is now coming from or going to Bison as opposed to running on the old main west and south from Hornell into PA and OH.  Coal and sand traffic is down from even three years ago, but stacks and tanker traffic is up. 

Traffic between Bison and Hornell is probably up over the old days since everything is now running on the line.  Not counting extras, there are six to eight trains each way daily plus one or two CP and CN run throughs.  Eastbound traffic splits at Binghamton with some heading up CP's D&H to Mechanicville and some down the D&H to Sunbury, PA and on to Harrisburg.

Poppyl

Thanks for the info.  What exactly is the Lehigh Line?

The NS Lehigh Line runs from Croxton yard in NJ to Allentown, PA.  Most of the line is the old Lehigh Valley main, hence the name "Lehigh Line."  From Allentown most of the NS traffic heads down the old Reading toward Harrisburg but a couple of dailies go up the Reading, Blue Mountain, & Northern to Scranton and up to Binghamton on the previously mentioned CP/D&H.

Poppyl

From Allentown the NS uses the former East Penn Branch of the Reading to Reading, PA. From Reading, trains head to Philly on the former Reading Main Line, or to Harrisburg on the Lebanon Valley Branch, or north on the former Reading main (now owned and operated by the Reading, Blue Mountain & Northern) to Port Clinton, Tamaqua, and the "coal regions."

The former Rutherford Yard of the Reading west of Hershey has been rebuilt as a huge intermodal facility that runs 24/7.

The Lebanon Valley Branch meets the Pennsy Middle Division just south of the Pennsy/Amtrak station. Trains still use the Philadelphia, Harrisburg & Pittsburgh Branch bridge across the Susquehanna (north of the I-83 bridge) and proceed to Shippensburg, Lurgan and Hagerstown on the Western Maryland-Reading "Dutch LIne."

I miss local passenger trains. But the Reading is by far the busiest survivor of "the anthracite roads." NS and the BMR&N keep rails polished. Even segments of the Catawissa Branch and the Lancaster & Columbia Branches are still in use. Tracks are gone in Ephrata but the restored station stands. So does the station in Lititz, next to Wilbur Chocolates, with a Jersey Central caboose for good measure.

More Reading locomotives, cars, rights-of-way, and structures are preserved (and active) than all the other anthracite roads put together. Sad for fans of those roads.

So the eastern part of the former LV mainline is dense traffic while the parts northwest of Allentown are essentially a branchline...throuh Towanda etc...

Where does the main flow of NS traffic from Philly to Harrisburg fit into this?

All very interesting btw.  I appreciate the replies.

The East Penn Branch from Allentown and the Lebanon Valley Branch from Harrisburg meet at Reading and join the former Reading Main Line to Philly.

Just about anything turns up on these routes. The NS Reading BEE LINE Heritage Unit came through on Valentine's Day. But I couldn't get there to see it because of the snowstorm. The Red Unit or the Blue Unit of the Ringling Brothers and Barnum & Bailey Circus Trains pass by, too.

The Reading line looks really busy.  Wonder why it was reduced to single/double track when there are other lines that remained double track with less traffic.  Also, is it CTC or only ABS?

I would say NS views the R&N line from Allentown to Scranton (former LV) more like a secondary rather than branch line given that they, as well as CP, run it pretty consistently.  The old LV west from Scranton to Sayre is R&N exclusively.

Poppyl