Waze Traffic

I have been using Waze for a few weeks now but I never used it for navigation until now.  A friend of mine had a house warming party, so I didn't exactly know how to get there.  To make matters worse, it was raining out.  I was planning on taking 476N to 76W into North Philly.  Imagine my surprise when Waze wanted me to take 476S to 95N.  Before I get to 476, Waze starts listing all the traffic reports.  It lists moderate traffic on 476S.  Why would Waze want me to go that way?  The traffic reports kept coming.  There were disabled vehicles and slow traffic all over.  Then, one report caught my ear.  There was an accident on 76.  Anyone from the Philly area knows what that means.  At that point, I decided to follow Waze's advice.  Although it still took me a while to get to the party, Waze made sure I didn't miss the party.