While driving and using maps app, my phone screen turned blue and then black, now I can't power up.

Hey Steve,

Welcome to Apple Support Communities.

This article provides information and troubleshooting suggestions that can help you resolve the black or blue screen issue with your iPhone 5s.

Get help with the screen on your iPhone, iPad, or iPod touch - Apple Support

If you see a solid color screen (black, white or blue)

1. Plug in your device to a power source. If you see the low-battery screen when you plug in, let your device charge for at least 10 minutes (20 minutes for iPad) before using it.
2. Reset your device while it's plugged in.
3. If resetting doesn’t fix the issue, restore your device.
4. If you still see the issue after you restore, contact Apple Support.

So long,

-Jason