• What would the equivalent MD purple line look like for Septa?

  • Discussion relating to Southeastern Pennsylvania Transportation Authority (Philadelphia Metro Area). Official web site can be found here: www.septa.com. Also including discussion related to the PATCO Speedline rapid transit operated by Delaware River Port Authority. Official web site can be found here: http://www.ridepatco.org/.
Discussion relating to Southeastern Pennsylvania Transportation Authority (Philadelphia Metro Area). Official web site can be found here: www.septa.com. Also including discussion related to the PATCO Speedline rapid transit operated by Delaware River Port Authority. Official web site can be found here: http://www.ridepatco.org/.

Moderator: AlexC

  by PHLSpecial
 
Septa has a lot of lines going into downtown Philly but no lines that go cross town from suburb to suburb. If Septa was to create the purple line what would it look like?
  by andrewjw
 
There are two big issues here:

1. Demand patterns - There are a lot of sprawling suburban residential neighborhoods, but it's hard to find walkable employment centers with the same job density as Bethesda and Silver Spring. DC has a ton of (government and government-adjacent) jobs in suburban business centers, whereas the Philly area has fewer, and they're much less conveniently located for one line to connect them up.

2. ROWs - the DC area has a lot of former trolley ROWs preserved as trails. The Philly area has very few, because the city proper was mostly served by street running trolleys and the suburbs by extant heavy rail. An easy way to see this is to look at the bicycle layer on Google Maps - there's barely anything once you exit the city itself that doesn't parallel a rail line with modern service. Branches like the one west from the wye at Oreland or the old PRR Havertown branch have long before lost their ROWs.

Here are a few ideas but I don't think any of them are really ideal:

Paoli and West Chester are very far out - at the point where you build a spur of the Main Line parallel to US-202 down to connect these, you'll probably get a lot more riders by using it to provide faster West Chester service to center city than you would by sending it to Norristown and KOP. But there might be a way to run 79mph heavy rail that stops in Fort Washington and Willow Grove on the way to Trenton, providing useful onwards travel. I'm sure NS would hate it, so you'd probably have to be running in the other trackbed and build passing loops, limiting frequency.

Connecting King of Prussia to the NHSL mostly fits the bill here. Upgrading the Media and Sharon Hill lines to modern LRVs and improving their grade separation and signal priority to build more LA-style light rail, along with an extension of the Sharon Hill line to the Airport, might be a good candidate here?

Looking for ROWs, consider the areas I-476 passes through are not very built-up or walkable - except for Media, and a faster Media LRV meeting the route 100 accomplishes some similar travel itineraries. On the north side, similarly, if you were to build a route down US-1, you'd get a lot more traffic sending it to Center City on the BSL express tracks than continuing it southwest to Manayunk or Bala Cynwyd. And there aren't a lot of people who would take a train that runs from the West Trenton line across the Wyncote wye up to Fort Washington.