Improvements

At first…
There are highways and smaller ones. There have been times that my direction is through smaller ways, avoiding a highway even if there is no traffic. When you ignore Waze and finally follow the highway, the elapsing time is faster than the initial advice.
Secondly…
There are fast roads and slow roads (too many STOPs, bad surface etc). The driver should be able to name those roads through a new button, so that waze can advice this road against another, even in there is the same distance.
Personally, waze has never automatically changed my root even when there is traffic ahead. Stuck in traffic, one can MANUALLY select the option:other roots and then a faster root is shown. But people, this should be automatic…
Finally… there are fast and slow traffic lights. Drivers should be able to inform the community through another option button, so that root advice could possibly avoid such traffic lights

All of the things you mention are captured within the app and the waze routing server. The data points that are captured when people drive with Waze active will help to aid in traffic light timing and the given speeds that are typically driven on that road. If you’re having issues with the routes that Waze is giving you, you can teach it to take you on the routes you prefer, but this isn’t ideal of course. There could be map issues in your area. Where do you typically drive and encounter these issues? We can have local editors look into this and see if there are issues in the specific areas that need to be addressed.

In what area are you having problems? I can refer you to editors in your area who will best be able to help you.