My daughter and her friends are driving to Philly for the 4th to attend the festival and watch fireworks. They will be driving from the VA/DC area but don't want to drive into the city. They want to park away from the congestion and then take public transportation. Here we have commuter parking lots all over the place. I'm not sure how it works there. Could anyone share advice on a safe place where they can park/ride for the event? Thank you in advance.