Waze does sort of learn routes.
The routes are based on the speed data and map data available. I had a big map editing spree on my potential commuting route, clearing up a lot of minor problems. I also deliberately drove some alternative routes giving similar times. Now Waze seems to offer some very sensible routes enar me. So, edit the map and drive the routes. If your route is genuinely faster it should show up eventually.
The route-learning happens at the Waze server end and not on your device client. It may take a while for it to have all the available data to give the route you want. Also - driving the clear side streets may feel quicker than sitting in traffic on the highway but it might not actually take less time.
