I've experienced this from time to time, but most recently today. After a few minutes of driving, my screen goes very dim. It does not turn completely off (sleep), it's just dim. I have to tap the screen and it goes back up to full brightness again for a few minutes.
I've tried other things but to no avail:
-Unchecking and rechecking prevent auto lock in Waze settings.
-Swiping up and adjusting IOS screen brightness to the minimum value, then back to the maximum value.
-Going to the home screen, then going back into Waze.
-Unplugging the USB end out of my USB to cigarette lighter adapter and verifying phone went to not charging. Then plugging USB back in and verifying phone went back to charging.
Note, I swapped to Pandora radio and that was 100% brightness for as long as I had it up, so the problem is Waze, not the iPhone.
I am on IOS 7.1.1. I heard IOS 8 is coming out this afternoon so maybe I will try to load that on once it is available. New iPhone 6 plus is on preorder so maybe when that arrives it will be fixed since it is a completely different screen (size and resolution).
PA, USA - iPhone 6 plus - Latest WAZE from the App Store - Map Editor Level 1 - Royalty Wazer - Rank 2,214 and counting.