Does google maps navigation have independent volume control?

I use google navigation on my m8 all the time, and I play podcasts or google play music all the time.

The problem? While the nav voice does dim/cut off the music volume or podcasts when appropriate apps are used, the nav voice can be EXTREMELY LOUD. Not all podcasts/music is recorded at the same volume levels, sometimes you need to adjust the volume up or down to hear at optimal levels, it would be useful if the nav volume could be set lower than the same as the general android music volume settings.

If there is an option for this, I can't seem to find it, and so I turn to you. Someone must have an answer.