Question

why the word AMBULANCE is written as ECNALUBMA in an ambulance van

Answer 1

The most common modern usage of mirror writing can be found on the front ofambulances, where the word "AMBULANCE" is often written in very large mirrored text, so that drivers see the word the right way around in their rear-view mirror.

Answer 2

become its reflected image will show the word AMBULANCE in the side mirror of vehicles