Thread by @A320Lga

Thinking a bit about alignments for Phillipsburg-Allentown rail service (which is so, sorely needed). The route choice is surprisingly complex.

Phillipsburg-Easton is pretty easy -- you just follow the former CNJ ROW across the Delaware and Lehigh, and you get a stop just south of the downtowns in both Easton and Phillipsburg. Not perfect (you'd optimally run through the activity density), but workable.

From there on out things are a bit less pretty. You can continue following the CNJ, but that means you'll be under a cliff from the denser residential areas of Easton. Elevators and all would help, but I suspect that 10 min bus service would be much more effective in these nhbds

Bethlehem is also a bit annoying. The highest job densities (albeit ones drowning in parking) now lie south of the river in the casino on the redeveloped steel mill site, which lies along a (very active) freight line.

The CNJ puts us on the north side of the river, which is the wrong side for a river alignment, and the wrong location for a north side alignment. The CNJ is also a trail at the moment.

It is likely possible to get 2 semi-exclusive passenger tracks in on the south side, but certainly not without paying large sums to NS for the privilege.

Allentown is also hard. If you stick to the north side, you'll end up in Allentown Yard which...no. If you navigate Bethlehem on the south side, you'll be well positioned to bypass that yard but you'll end up along the Jordan Creek maybe 1/3 of a mile west of downtown Allentown

I think all of this points towards the advisability of a tram-train for the region? There would be some real issues to resolve with transit priority and street width in these older CBDs...

...but insofar as it'd allow you to use high-quality rail ROWs btwn towns and streets which touch jobs/people in towns, it seems the smart move.

(BRT, if done right, could also perhaps work, though you'd likely not be able to recycle the rail ROW)

This feels more broadly illustrative of the sometimes-present issues with recycling rail ROW in places whose topography is similar to the Lehigh Valley.

Lots of times, RRs will end up along rivers cut off from population by cliffs, or by now-dormant industry that grew along the tracks

Those barriers are by no means insurmountable, but especially given how poorly integrated land use and station access planning are with the design of transit corridors, it's not uncommon to end up with beautiful but empty cliffside stops.