In my area Waze does a better job at anticipating future traffic patterns. For example, every Thursday I have to get my son from school and drive across town starting at 5pm. It's a 20 minute drive if there's no traffic and 30-35 minutes typically and we only have 40 minutes to get from A to B. Google will pick a route that is fast at 5pm, but builds a lot of traffic at the Nike headquarters by the time we reach it 15 minutes later. Waze seems to understand this better and has never routed me into that traffic jam.
