Same problem here. GS3, stock Android 4.1.2. A few months ago voice commands for traffic or hazards used to work. But no more. What is frustrating though is that once I reach my destination, if I wait for a bit and fire up waze again, and "test" a voice commanded hazard, it hears me just fine. It's only when I'm underway it doesn't work. A fix here would be HUGE, because as mentioned by others, feeding back this sort of road intel to the community via screen taps is way to dangerous. The voice idea and menu structure I think was well thought out (when it worked for me way back when anyway). But now I am no longer able to contribute feedback to the community.