Philadelphia is way off it’s historical high population period of close to 2,000,000 from the late 1940’s through the early 1960’s, so is massive core employers (Navy Yard, Arsenal, et al.) which today are non-existent, and the center city central business area has never been a strong magnet area as compared to the once outstanding and thriving blue collar and manufacturing. More importantly, the one very high population density that was at or greater than 20,000.00/square mile is now about 10,000.00/square mile.
Does street-running rail make any sense now or for the near future. Moreover, the FTA, and other government agencies, how would they interpret the current facts and projections in the process of grant making?
Let’s look back at the Schuylkill Valley Metro (SVM), the concept is good for light rail transit, but in this case, not quite as overreaching or ambitious as the past proposal, but utilize one of many underutilized and disused rail lines. Norristown Transportation Center via Bala/Cynwyd, one of the two Chestnut Hill line etc. are all possibly workable examples.
Also since new shops, infrastructure would be required, switch to standard US rail gauge should be considered, as this may lower vehicle cost somewhat now and later on when replacement is needed.