How to set the google maps app foremost while driving I have been using google maps for a while now as my driving guidance/maps app. It does have one slight inconvenient, while you are driving you'll get all notifications to still crop up space on your screen, and for some apps they might even get in the way of your maps.   

Is there a way to keep google maps, or any other maps app for that matter, foremost on my screen?

If I set the phone in driving mode, can I stop other apps from getting screen space/time all at once or is it in a per app basis?
Use Android Auto.
This will reduce the accessing time for Maps or Any other application required while driving. Also During driving and using android auto, you'll have a better experience of Map as the notifications from other apps won't bother you as they do on running the Maps app directly.
Reason for this is to minimize the interruption of other apps while driving.
Android auto is designed with keeping these points in mind and to make driving safer.