(northwest is up)
Drawn from memory, after my cognitive neuroscience proseminar was discussing spatial representation in the hippocampus. I got it pretty much right except the scales are somewhat exaggerated around Anna's house and i screwed up the Montgomery Ave curve - it should be parallel to Lancaster farther east.
I mostly did this by listing off intersections one by one and thinking "ok, what comes into this intersection, what will it have to connect to, what will it have to be between" ... once I satisfied all the constraints, the map pretty much drew itself. Amazingly, Old Gulph Road isn't as scary and complex as it seems, if you just take it section by section.
For comparison, Google Map of the area.