Why aren't South Indian languages written in Devnagiri script?

 Thank God, South Indian languages are not written in Devanagiri Script.

I mean it truly, in Modern days, with excellent High Ways and Transportation Systems, the majority of States miserable in writing sign boards. It is hapazard - spending millions in making highways and you failed to read what is written in sign boards.

I have seen in Gujarat, the busses ply empty. There is one board at the front, even you cannot read the number forget about reading the scripts. There will not be any light in the night to read the destination properly. On the contrary, the busses in Tamil Nadu will have atleast two boards in the and back. Over and above, the entire route is written all around the busses plying to rural villages.

The signboards in NH and SH are miserable. Unless you are familiar with the road, you will end up somewhere else. The scripts are visual to tell you the quality of life you live.

Scripts are not to bark your pride. It should be useful for day to day life.

Tamil has its own scripts like devnagari. Certain minority languages such as Saurashtra, Badaga, Irula and Paniya are also written in the Tamil script.

Saurashtra is an Indo aryan language spoken primarily by the Saurashtrians of South India who migrated from the Lata region of present-day Gujarat over a millennium ago.

Badaga has similarities with neighbouring Tamil - Kannada, and has now been identified as an independent language.

Paniya is one of the Dravidian language. It is spoken by the Paniya people with a majority of its speakers in the state of Kerala.