Who might find it very useful to have an accurate 3d map of a route embedded in their vehicles or used in training simulations

teachers
first responders
plumbers
gamers

First responders would find it very useful to have an accurate 3D map of a route embedded in their vehicles or used in training simulations.  

Explanation:

First responders are the people who arrive at a location when there is an emergency situation at the location. Accidents,natural disasters as well as terrorist attacks are considered as emergency situations.

Police officers, firefighters, paramedics etc are examples of first responders.  

There are different types of first responders depending on the nature of the assistance they provide. A route map fitted in the vehicles of first responders help them reach the emergency site soon.  

answer; attention;