They already have apps that warn you are in a high crime area....
I bet I know how it works, if you're within a mile of "MLK Blvd" it flashes an alert.
Its called a street sign that says “MLK Jr Blvd”
Low Information - High Crime
I recall somebody tried to make a phone app or plugin that allowed you to navigate around those areas.
Then apple or google blocked it because they said it was racist...