I have never been to Philly, but can highly recommend the segment explorer on strava.com. You start by putting in the city and the zoom level of the map will show the most popular segments ridden. Zoom in you'll get a finer grain of segments in that smaller area, zoom out and pan around to the Glenside, PA area.
If you click on a segment you will see the leader board and see how many times it has been ridden, you will find some only ridden by one person, probably not a popular route, but others ridden many many times would be a great place to start looking.
I use the Strava segment explorer whenever I travel to find bike and running routes while on my trip, it has proven to be very helpful to me in finding new, safe places to bike and run.