If you think you've found a bug on the website which isn't specifically an App or Map Editor problem, or have a request for new or modified feature of the Community, Forums, or Waze website, use this forum.
Nope. Just like many apps, volume adjustment is system only. I've noticed a lot of apps which have a volume slider (radio-station apps, for example) appear to also just adjust the system volume. It'd be nice to have an option and I'm sure someone has already requested it. Head over to the Client Uservoice and search for it.
I agree. I wish there were a way to adjust the volume level within the Waze app. The reason I noticed an issue was when I was listening to my the iPod within my iPhone the volume of my music was much quieter than the navigation voice of Waze. As a result, normal listening volume for music is interrupted with very loud navigation directions.
Re: volume control (iphone)