You re walking through one of the safest areas of the city. Chestnut street has plenty of shops on it which means there will be a lot of people around doing last minute shopping for Thanksgiving. I really wouldn t worry about it. I ve walked through this part of the city plenty of times and have never felt the least bit endangered.
There s every chance that you will be fine, but be careful. Keep your wits about you, do not listen to an MP3 player so that you can hear anybody nearby and keep your cellphone in a pocket where you can reach it easily - but don t carry it in your hand as it may attract thieves. Try to stick to well-lit areas and, if possible, places where there are a lot of other people about. Pay heed to the local knowledge below - I ve never been to Philadelphia so all I can offer is common sense. Local knowledge is invaluable.Better still, could somebody meet you at the station? You re always safest with somebody you trust. Or could somebody lend you the money for a cab?
If you walk out Chestnut St. and make the right on 30th, you should be fine. That s a pretty safe area.