You may luck out and not encounter this, but...
Currently, Light Rail is on bare-bones service. That means:
One car (two articulated cabs) per run...
...which are running late, by default 40 minutes...
...and is automatically full (to Japanese/Chinese standards!)...
...and the Penn-to-Camden train is canceled (Bus service to Mt. Royal).
This is due to a discovery of cracks in the wheels, causing a manditory inspection of the 52 car fleet. This also means... it won't be until late July until it's supposedly done.
My suggestion: If you're flying in on Thursday or Friday an